Yeh im looking at this for my 1k in melbourne too, I'm yet to see one but think it'd be wise to fully read up on the vicroads site as they seem to have a system in place if youre planning on putting a more powerful engine in you need something called a VASS Approval Certificate apparently.

VICROADS MOD PAGE
I rang one of the VASS guys on the list provided by vicroads and the charges start from $350 just to look at it! then the certificate is about $400 then more if you want further tests (brakes ect)
He told me the car needed to be roadworthy...I said Oh...I need a RWC before I see you? then he got all crabby almost yelling no no im not looking at a car thats not roadworthy...well der at $350 a pop you think im going to rock up with it held with gaffa?
So yeh thats my not-so promising start, I think I decided to just take it easy and do up the car bit by bit before even considering it now...oh and ill be looking to deal with a VASS accreditor WITHOUT the attitude.

Good luck, let me know what you learn and ill do likewise