Hey Greg ... are you still with us?
Your thread sorta got waylaid there for a while. Happens sometimes on this forum, but we get there eventually, sometimes.
I know you're in NSW but are you close to Sydney? If so your best bet before you make any decisions or outlay any cash is to get along to a Sydney club meeting and have a look at the cars and chat with the guys. There are several kits you could use as a starting point or as some have already mentioned, you could consider a previously owned one. I'd be a bit wary of "unfinished projects" unless you have someone very experienced go over it with you, and you are confident in your own ability to rescue it and take it to completion.
You've already been in contact with Treeve I assume, so you've some idea of the legalities and compliancing side of things. If you embark on a build, you should establish a working relationship with him to ensure your progress is in the right direction. A good engineer is like gold.
Lastly, (you listening Spooky?) I would suggest you contact Warren at Absolute Pace (warren@absolutepace.com strangely enough) for an information package on their product. I realise this may appear outside your budget from what you've said but as others have mentioned, very few of us have the money up front for the whole package. It may be that you purchase whatever level of starter kit you want and then enjoy the build over a year or two -- it all depends on your ability, whether you do in fact enjoy building as a factor of ownership. and of course garage/workshop space and an understanding other half, if applicable. But in any case I would recommend that after reading the AP literature, you get yourself up here for a good squizz at the AP operation on the Goldy.
Once you've talked to the Sydney guys, had a look at what's on offer there, decided whether you want to build from new buy secondhand or rescue a stalled project, checked anything you're unsure about with Treeve, perhaps contacted Neil Streeting in Sydney who has built several Cobras for customers, emailed Wazza, got the goss on the APs, maybe been in touch with the Melbourne club to see what's going on down there,and finally taken a trip up here to Godzone to look over the AP establishment ..... phew, after you've done all that! ... then you're in a position to decide where to next.
Buy an existing car, have a new one built by the factory or someone like Neil or Scott Hampson (Venom) up here in Brisbane, or build one yourself. It all depends on what YOU want to do. Good luck with whatever road you take and remember there are always plenty of people in the clubs who are happy to help with advice and suggestions.