there's already a pretty active community in the UK for skylines (you get all the models there that we do), jump on gtr.co.uk and skylineowners.com to find some locals who have one so you can go for a spin in their car with them to see if you really like em.
Series 1 R33's these days are about 12,000 max, series 2's will cost you 20,000 max, and it better be real good for that price tag, as you can get R33 GTR's for about 24,000 these days. R34's are also just starting to creep under the 20,000 mark, so why not go for something newer. Car Sales is a pretty good place to start, i'd also be checking out ebay.com.au and tradingpost.com.au