^ nah the cheap short shifter alternative is the Z3M, it has a shorter throw compared to the E36 M3 (feels same like ur ori)...no need to dismantle GB. if you want the real deal then get an UUC EVO3 SSK which comes with the DSSR (Double Sheer Selector Rod), but the $$$ is very steep..
I've never driven a SSK equipped e36 before, but the advice I've heard is to actually try out one before committing to a SSK. Whether you like it or not is a personal thing.