Dont bother. Too many people who have no idea about cars buy a shit box and try and turn it into something it just isnt. Do you have any idea how much money and work it'll take to convert your car to turbo? And even then you can only run a small amount of boost before the engine blows up. Sure, you can build the engine with forgies, but $20k later and you'll have a car that'll MAYBE keep up with my R33.
Mate, its a bunky. Keep it that way. Drive it around as a bunky until you're off your Ps and save all your money. Then when you're parents let you get a turbo car, get an R34 GTT or something. Trust me, I wasted too much money on my NA, and while I dont regret, I could have done it better.
What about your NA R33 and your R33 GTSt?