The interior is slightly different, the R34 N/A lacks the three gauges that the turbo model has.
Im pretty sure the N/A model has smaller brakes.
Not sure about suspension differences.
Chasis is the same.
Leave your standard frontbar on there until you can afford to respray it the same colour as your car.
You probably should of savedup enough for both the bodykit and frontbar before you brought it.
You could easily get a R34 25GT-t for that amount of money, R33 GTST's will be around 11 - 16k, R32 GTR's 19k+ & you ca nget R33 GT-R's for high 20's low 30's. But be sure to factor in registration, insurance tyres and such.