Jim?

They both come in RWD and 4WD models, depenmding if you got a GTR or not

Main advantage of 32GTRs is lighter than 33GTRs (over 100kg if early models) and you can feel it too, cheaper, and come with a push clutch, which makes things slightly cheaper/easier than 33s and their pull ones when it comes to uprated clutches.

33GTRs allegedly have a faster acting 4wd but youd be hard pushed to tell. They also have bit better brakes.

Apart from that they almost identical in spec, engines are exactly the same (tho allegedly 32s have stronger blocks), and box n diffs are almost the same n just as strong, just down to price n personal preference.

GTSTs are very different, and RWD.
R32 GTSTs are 2litre 6cyl 24v as std, R33 GTSTs are 2.5, but heavier again, but with better brakes, and same barring that again really.

R32s also have GTST4s which are the 2litre, but the GTRs 4wd, so perfect for a cheap car to swap to a bigger engine in...

Anything else you wanna know?