Volume builders build volume houses. Its that simple. We have built twice now, and my advice is to go through a private builder. It will cost more but you can get whatever you want. It will cost more and take longer but its well worth it in my opinion.
We have discussed moving from Melbourne at some point but honestly, Sydney is a massive shit-hole, Queensland too hot, Adelaide is..well... Adelaide, Perth I have never been to (might be an option but its virtually another country that far away?) and Tasmania is beautiful but far too small and far too fucken cold - even for a guy from Melbourne lol.