Another confused newish rider
Welcome to Boardworld, Leez. 
Firstly, here are a few links and resources to answer some of your questions. Please feel free to reply in this thread or any of the others if you have questions or need clarification on anything.
Switch Riding (scroll down)
Terrain Park Safety (covers etiquette, same thread as above).
Tricks (this is a new thread but covers the basic principles of freestyle progression).
I weigh approx. 70-75kg, 168cm tall (5"11), would a 155cm board be suitable for what I want to do? EDIT: My shoe size is 12 or 12.5 (not sure of my boot size, no good snow stores in Perth…), do I need a wide board? I kind of don’t want one… to me it seems like wide boards are a bit of a disadvantage in the park and for manuverability or am I just being silly?
Yeah, something around the 155 / 156 mark would be ideal for freestyle. Not too big, not too small - it’s going to be a nice size to progress your skills on.
It’s important to work out what size snowboard boots you are. I guess you really don’t have much choice other than tracking down a snowboard store in Perth and trying on some boots. If you wear a size 12 shoe, chances are you’re going to be a size 12 boot or smaller. As chucky mentioned, with the reduced foot print on some boots, you could really get down to a size 10.5 foot print. This really depends on which boots you buy.
OK, let’s assume you are a size 12 boot. Yes, you will need something ‘wide-ish’ to accommodate your boots. Something around the 257mm mark would be good. It’s not going to be a disadvantage, you have large feet so you have the necessary leverage over the board. It would be a disadvantage to someone with a small foot. If you get on something too narrow, that will be a disadvantage; you lose stability and you risk boot drag.
At Hakuba, I found on longer runs or extended sessions the soles of my feet were really caning. I don’t know if that was just crappy rentals or my technique?
Most likely the poor fitting rental gear.
When I get my own board I want to try and use a duck stance, 15deg front and -9deg back centered stance right?
That’s a safe starting point. Make sure you play around with your stance; try different angles, trying different widths. There’s no right or wrong here. Start with that, then try something else - feel the difference and eventually you will know what’s ideal for you. Also please read this thread.
Do you know what size binder I need?
Large.
Ok looking at the front page snowboard, I’ve sort of narrowed it down to:
Arbor Westmark 156
Arbor Formula 155
Forum Scallywag/Manual Chillydog 155/156
GNU Carbon Credit 156
LibTech Attack Banana 156
Nitro Gullwing 155
Rome Garage Rocker 157 wide
YES. The Basic 157
There’s some excellent boards in there but I’m curious, why are you limiting yourself to those boards? For example, why wouldn’t you consider Burton? Something like the Burton Joystick 156 wide would be awesome. 257mm waist is ideal and it’s a super fun freestyle board. Just putting it out there.
Let me know if you have any questions. 
How was the overhang on the 155 that ya rode, Chucky?????
23” centred stance at +18/-9’, no worries at all - and nice snappy edge-to-edge transition.
The 249WW is the same as my Burton X8 155, which is my current all-mountain board - and I’ve never had a problem with toe/heel drag no matter how far I lay it over. Contrary to Burton’s published specs, my 2009 Vapor has a WW of 247.5 (they claimed 249) - and on first ride with non ‘Shrinkage Tech’ size 11 Burton Ions, I experienced minor toe drag on my back foot. Problem solved with my new Burton SLX boots.
I should also add that my bindings have custom 1.5mm thick compressed neoprene dampening pads underneath, which raise them up ever so slightly off the board. When considering board widths, you need to also factor in how high your bindings raise your boot off the board.
Amazing replies, thanks :D
The reason why I didn’t consider Burton is pretty silly actually… I thought they were a little too… common 
Like Commodores (or should I say ‘Commonwhores’).
I did read those threads Jeremy, just wondered if anyone had any other tips that weren’t on those pages Sorry, I should have clarified!
Cool I had no idea about Shrinkage Tech I’ll look out for it! Ok so I gotta look for a waist width of approx. 257mm and large bindings. Narrows it down a bit :D I guess the best thing to do now is for me to look for stores in Perth and try on boots to find out my size.
Ok so I gotta look for a waist width of approx. 257mm. . .
Except if you get Shrinkage Tech - then you can go down to about a 253mm WW.
Ok, I think I’ve got it sorted:
YES. The Basic 157W (can’t go past the looks, absolutely love the clean look). The WW is 260mm, too wide?
or
Burton Joystick 156W
Burton Freestyle bindings
or
Rome 390s
Opinions?
I found a local Mainpeak store and is probably the only store in Perth that has a half-decent snow range haha. I can get the Joystick and the Freestyles there so that’s a plus I guess. Though the Joystick is a little on the expensive side there, 550 bucks. Freestyles are 200.
Help me pick out some boots? http://www.mainpeak.com.au/snow/snowboard-boots/products.html
I don’t think any of them have shrinkage tech though unfortunately :(
What price can you get me for the YES Basic and 390s Jeremy? 
I have size 12 DC boots and have been riding a normal width 159 skate banana @255mm waist, I then got a 157 T Rice that was sposed to have a 257mm waist width but buggered if it’s any wider than my banana when I put one of top of the other however I don’t have any issues with toe drag but I ride +15 and -15 stance which might help. I guess the magnetraction probably makes it harder to compare the two. If I was you I would go with a rocker board, made my boarding so much more fun when I was starting out. The carbon credit is a great board, good value for money I reckon but there are a lot of boards that are fairly similar.
Spend some time with the boots, don’t go buy some from a store in Perth just because they are the best fit out of a very small selection. If they are not 100% comfy don’t settle for em, hang out till you get to NZ and go find some that are really comfy. My GF made that mistake and ended up with a pair of boots that made boarding very uncomfortable for her, not a good situation.
If price is still an issue once you have found the make and model that fit best ask around and see if any stores have last seasons version of it which will be a better price. Generally speaking the fit won’t change much if at all just colours and maybe a tech feature but try them on first just to be sure.
As far as brands go, everyone has their favourites for whatever reason, there is nothing wrong with Burton, you don’t get to be that big and successful by selling shitty gear, most of my outerwear is Burton stuff and I almost went a pair of their bindings this year. I like Ride bindings but my mate got a pair of K2’s that look really well put together and light as well, my Rides seem to be fairly indestructible and reasonable weight. I would like to get the opportunity to ride with some different gear next year but constantly chopping and changing is kinda detrimental to your development early on I reckon.
YES. The Basic 157W (can’t go past the looks, absolutely love the clean look). The WW is 260mm, too wide?
or
Burton Joystick 156W
No, I don’t think it’s too wide, especially if your boots at around the 12.0 mark. Both those boards have some degree of rocker (YES with CamRock and Burton with V-Rocker), which will make them quick and easy to turn anyway.
Either of those boards would be great. They are a bit different to each other so I will point out the differences:
The YES Basic has CamRock; which is camber between the feet, and rocker in the nose and tail of the board. The camber provides stability, edge hold, and energy. The rocker gives the board a really fun and loose feel, quicker turning, and better float in powder.
The Burton Joystick has V-Rocker; basically full rocker throughout the board. Fun, playful, easy to ride, great for learning new tricks, excellent in the park etc.
The camber profiles would be the most noticeable difference. The Basic is going to be more versatile than the Joystick. Both these boards are excellent and I can safely say you are going to love either.
Burton Freestyle bindings
or
Rome 390sOpinions?
Between those? Definitely the Rome 390s. The Burton Freestyles are entry level, would be similar to the hire bindings you’ve used. There’s no comparison between the two. That said, Burton make excellent bindings. Look at the Missions (at least) or Cartels if you can afford them.
Help me pick out some boots?
Unfortunately, that’s impossible over the internet. With boots, you need to try them on. You really need to have a proper boot fitting session with a good range of boots and a good boot fitter. Otherwise you will have serious problems. I agree with nthnbeachesguy; if you can’t find a good range of boots in Australia due to your location, you’re better off waiting till NZ - as much as I hate to say it. Unless you can pop down to Sydney for half a day before flying out?
What price can you get me for the YES Basic and 390s Jeremy?
Leave it with me. I’m speaking to Amine (YES rep) today. I know the Basic pretty much sold out Australia-wide this season, but there might be new stock coming in soon. Anyway, I’ll see what I can do and get back to you.
EDIT for rider’s post “The Burton Joystick has V-Rocker; basically full camber throughout the board. Fun, playful, easy to ride, great for learning new tricks, excellent in the park etc”. Joystick has full rocker not full camber
Good find, Skip. That’s what I meant to say. Fixed my post. 
YES Basic 157W + Rome 390’s + Boots that are right for you (with a soft to mid flex) = A great combination!!!!!!
If you didn’t want Burton because everyone rides them, just stay away from the Custom. There will be 100’s on the mountain on any day. In our shred, there were 2 from people bringing them down lol.
I agree with the Yes + Romes. If you went with the Burton board, I’d always go Burton bindings (Missions / Cartels / Malavitas) but if you can get the 390’s at the same price as the freestyles, I’d go the Yes.
It’s a mid flex board with Cam-Rock which would be great for a beginner / intermediate.
It is super poppy off jumps
The 390’s are very good bindings that a lot of park riders choose, the Burton Freestyles are sold to punters without a clue or to rental companies as cheap bindings.
Just to give you a few options, you could check out the Forum Recon Wide 156, Stepchild Everything Sucks 155 Mid Wide, Capita Stairmaster 156 Normal (has a 255mm waist), DC PBJ 155 wide or a Lib Tech Skate Banana 155 non wide (255mm waist)
All are good boards and if you can find one at a good deal, you like the graphics and everything fits, I don’t see why not have a look around before committing.
Oh way to make my choice much harder TJswish I’ll check those out!
I’ve also got another mate that’s coming on the NZ trip who wants to buy a setup as well, so you have two sales here Jeremy He’s still a bit 50-50 as to whether he’s definitely buying one but I’ll make sure I point him in your direction. I also couldn’t find the Joystick on the STM website either, how much do you sell them for?
That’s how I roll mate. Just if you are trying to keep it on the cheap, pretty much all of the above will work for you. And all but the Joystick will work with the 390s
P.S. if your mate is a similar size and buys a board, you can always swap for a few runs and if you both prefer each others setup, work out a deal? lol.
Hehe, just to stir the pot a little. . .
If you could manage to find one (and your boots aren’t too bulky - 255mm WW), the early release 2013 Burton ‘Super Hero’ 154 ticks your boxes nicely.
Think of it as a ‘semi-Nug’ - you size down from your regular board like you do with the Nug, but only by up to 5mm with this one. This would give you the maneuverability of a smaller board with the stability of a longer one, the ease of rocker (rocker/flat/rocker) with the performance of Burton’s new(ish) Squeezebox technology, and the playfulness of a park board without sacrificing float in pow. Your switch riding would improve phenomenally with this board!
I WISH they had boards like these when I was starting out!!!
Unfortunately there are no YES Basic 157 wide snowboards left in Australia. They have all been sold. There is a regular Basic 157 though (251mm waist). The 2013 boards won’t be arriving in Australia until May 2012.
Not all products are listed on the STM website. Sending you a PM, Leez.