dude, buy a POS nissan pulsar or corolla for now (how about a ke70??? still rwd fun, and there getting VERY popular at the moment) can pick one up for $1000-$2000. and there a basic car to work on which will give you good experience for when the skyline comes along. and it wont be a big deal if you crash it (and there will be times when u come close to incidents/crashes, everyone has them)
chuck some old school jap wheels on there, stiffer springs and it will go til' the cows come home
u definately have to stage your cars capabilities as you get more experience, otherwise u'll kill yourself
for example:
1st- ke70
2nd- r33 gtst
3rd- r3x gtr/evo
4th- some feckin off chops thing