If you're coming back to oz in 2008 you should get yourself a nice little moneymaker car (ie one that's not eligible for SEVS and is highly desirable... like an S15 Varietta for example, or an extremely modded car) and own it for a year, bring it down as a personal import, sell it, use the money and buy yourself a R33 GTSt. You can buy a lightly modded R33 GTSt for between AUD $13,000 for a 1993 and AUD $19,000 for a 1998. No doubt in 2 years time they will drop further in price.
Already the focus has moved to R34's as the preferred Skyline to import (we've been getting quite a few inquiries for them and very late model R33's lately).
Also you'll have already paid import fees for the car to enter the UK, and from what I know of UK export laws you don't get them back or anything, so you might as well just import one direct out of Japan instead of paying tax on an already taxed car. Our taxes and duties aren't as hefty as the UK ones either. Shipping from the UK to Australia is also a lot more than shipping from Japan to Australia.
In summary, don't do it Pick one up when you get here.