Welcome.
some good advice above. I was in your boat a few years ago, the night was young and i was full of optimism....etc.
I personally wouldn't bother with an NA skyline or any overstated import for my P's. They are WAAAAYY overpriced, and a police magnet.
Also these cars are getting old so rust and general misuse and neglect is becoming more prominent on most of the GTS's and GTST's as every second p plater has them. Even some 32/33 GTR's arnt in too good nick anymore.
Buy a cheap-ish car, dont mod it (unless you HAVE to, and then leave it to basics), bomb around for 3/4 years, save your pennies then buy a decent BNR33/32 or whatever tickles your fancy when you get on your opens