Hi Miss V,
I am unsure about Qld, but from other threads it appears WA and Qld standard sales contracts issued by the respective REI's are pretty similar.
In WA, we've always had the same thing. Ressy or comm....doesn't matter, you're buying a piece of dirt....same same. Format is identical and conditions you place on your offer can be as many and varied as you so please. Just be aware the more you place on there for your 'protection', the more likely the Vendor will simply throw your offer straight into the bin.
We try and go with no conditions at all. Sometimes hard to do obviously, but the attractiveness and simplicity of the offer appeals to the Vendors. Less is better.
We have a worded 28 day DD clause, where we fluff around checking all kinds of stuff. Most Vendors won't accept it, some will.
The GST clause is a 1 pager, supplied by the REA. Just choose 1 of the 3 options and go from there. If it's vacant possession, you'll pay GST and then get it re-imbursed if you're registered. If it's a going concern...i.e. comes with a tenant then it's GST free, just like a house.
Good on you for having a crack at it. I wish you all the best.