you might as well try to put an F1 race car through the SEVS compliance procedure instead of the Z Tune.
Only option would be to get one that's already complied in AU, send it back, have it built and then come back...
Or move there for a year n bring it back.
I think from Nismo's selection criteria, the car had to be an immaculate R34 GTR with under 40,000km on the chassis, and the 100 that they were going to build were already purchased. So basically you'd have to buy the stock on from Nissan (or import it on a "loan") then return it, have it modded, then ship it back as a previously complianced car.