well, from what i hear... there are all kinds of crazy things you have to do to drop a gti-r into a 200sx.
*deep breath*
have to redo ecu to accept the 444cc injectors (not exactly plug+play, gti-r is the only nissan engine to use that size...), wiring is a nightmare, among other things...
get a bluebird or avenis (is that spelled right?) engine instead. they can be dropped in with about 1/3 of the work and none of the headache. while the bluebird doesn't start out with the same amount of horsepower as the gti-r, you can fix that by getting the turbo setup off a gti-r. Or, you could just spring for the newer avenis engine and get the same horsepower with, again, none of the headache.