Nice,
Nissan Skyline R34 Gt-t good choice of car.
I have actually done a wrtie up on my blog, it will give you an easy guide to maximising the power from your R34 Gt-t Skyline, has approx figures for both engine and rear wheel Kw expectations and approximate costings.
http://ozcarimports.blogspot.com/2008_08_01_archive.html
Good Luck