I have been dealing with "Builders" and brand new homes for 17 years and do alot of alarm installs and have done alot of camera work with well known companies like Metricon, AV Jennings etc etc. I have seen many many go broke, but a few have always stayed healthy which is good.
Metricon is a little pricey, but very good at its follow up. AV Jennings has been big in NSW for decades etc etc. I would ONLY stick to a large company, and it pays to look at their profit/loss statements for the previous and current year to date which they will be happy to provide (the banks wont release monies to these companies unless they can prove they are trading in the black etc). It pays to stay with a company that is healthy. You just have to be careful that a company like Metricon, who might be up 100 million for the year on its home building business etc, isnt 120 mil behind on its big commercial shopping centre/high rise business etc. In this financial climate, you have to play very safe. Do ya homwork and speak to a finance consultant/or the bank who will have up to date info on how these companies are trading profit/loss wise.
Stick to a proven and already used house design, it will save around 25percent compared to a oneoff design you get drawn up.