as you say but depends on who manufactures the turbo so it'd be best to phone around

rs turbo t3
std compressor housing ar 42, compressor wheel trim 45 exhaust housing ar 36
stage 1 usually bigger compressor wheel trim 270 bearing.
stage 2 usually bigger compressor wheel trim 360 bearing.
stage 3 usually bigger exhaust housing .48, bigger compressor wheel trim and 360 bearing.

2wd cos t3
std compressor housing ar 42, compressor wheel trim 55, exhaust housing ar 48
stage 1 usually bigger compressor wheel trim 360 bearing.
stage 2 usually bigger compressor wheel t34 trim machined to t3 housing 360 bearing
stage 3 usually bigger exhaust housing .63, t34 compressor wheel and t34 housing and 360 bearing

4x4 cos t3
compressor housing ar 42, compressor wheel trim 60 exhaust housing ar 48
stage 1 360 bearing
stage 2 usually bigger compressor wheel t34 machined to t3 housing, 360 bearing
stage 3 usually bigger exhaust housing .63, t34 compressor wheel and t34 housing and 360 bearing

I recommend cr turbos or universal turbos.