If they don't sell them in Perth, get them shipped over.
Those wheels are bad because quality is bad, and they are way heavier than Jap wheels
Check the trader section of http://www.nissansilvia.com/forums for more wheels
What do you mean by 'Aussie-sourced parts'?
As in components made entirely in Australia? Don't think there are too many of them and they would cost nearly as much as Jap parts (i.e a catback from Hi-Tech or CES would cost the same as a JDM brand)
We can do what's called a REVS check:
http://www.revs.nsw.gov.au/
Plug in VIN, engine and registration (license plate) number and it'll tell you if the car is under loan (the bank owns it) or if has been written off before.
Yes you can check if its been a write-off or still on loan but not accident damaged.
I would take funkymonkey's advice and go for something newer like the R34 GT-T.
I've always like cars that have the majority of mods from one manufacturer
eg
HKS pod
HKS FMIC
HKS Turbo
HKS EBC
HKS Suspension
Although sticking with only one brand may not be optimal for car performance...
So, name me the brand of the majority of your mods and also how many mods from that brand.