I wanated to know some of the stuff i could do with a 300zx n/a
like forinstance what engines i could swap with it and if it is fesable to do it cost wise and different stuff like that

Give me 3grand, and I'll give you a JDM 300ZX VG30DETT (Twin Turbo) clip. Thats the best swap you can do into that crammed little engine bay... Anything else your talking bad times ahead... Heres an interesting site.
http://www.meggala.com/hybridscss.htm
But basically what the clip is, is the car was wrecked in the back, so they took a plasma gun, and cut it in half, selling the front half for parts. Everything will be included in the clip, engine, transmission, ECU/M wiring, MAF, tubing, RHD (right hand drive) dash setup... Everything. Peace foo's :p

But if your talking simple HP shit. Get an Injen intake system, Twin Turbo stock MAF (Mass Air Flow meter) Stillen headers, and a good exhaust system... Good HP right thur. Peace foo's :p