there are no other tranny choices whe going with a 3b diesel... there is either the factory 4 speed or the factory 5 speed. the gassers with the 4 and 5 speed wont work becuse the input shafts are completely different as well. I also believe that there are no adapters made for the 3b diesel as well to adapt to a different tranny.... the 5 speeds have a 4.9:1 first gear though so its pretty good... if you found a JDM 4 speed than it would have the same first gear but good luck with that one...
as far as weight goes, i am pretty sure the engine, tranny and tcase combo weigh in at aboot 1500 pounds give or take 100....yes, its heavy!!!!!
the engine in stock form produces aboot a whopping 86 horse power but oodles of torque. I prefer my diesel over a gasser any day......for wheeling anyways. 8)
as for the turbo, you can turn your exhaust manifold upside down because it has the same bolt pattern either way and people mount anything from 2.2 dodge charger turbos to dodge diesel D50 turbos... I personally am going to mount a turbo for a cummins 3.9 engine....