G'day Vincent
You mention wanting to do a scratch build but don't have the time so how about you get yourself a nice GTD in the UK for around the £25 - 30K mark, drive it around and when you get to Australia you can then pull it down and fix up anything you don't like to your satisfaction. Probably the most cost effective solution for you as you get to drive it straight away, learn about the car and the things that you don't like, it's RHD, cost is reasonable and as there are 2 Australian manufacturers available there is plenty of scope for help when you are in the re-building phase.
My 0.02c worth
Bill