The Nissan 180SX is a brillant car
SR20DET makes a very quick car. Also brillant for drifiting
Unfortunatly the 240SX isnt very impressive accoriding to my mate.
The 2.0 Turbo is much quicker and so i would pick a 180SX over both the 200SX and the 240sx for obvious reasons!
As for moddifications there brillant cars to mod!! Great for getting parts from star companys like HKS & Blitz but be ready to empty your pockets a bit