What kind of power are you shooting for? If you're looking for 500+whp, none of the above options are even worth discussing. If you're looking to stay below that line, there are quite a few options that should suit your needs. None will be especially cheap. My daily driver will be getting a nice RA Frankenstein setup, but I plan to stay close to 300whp for the duration. I would not want any factory trans if I were headed to 450bhp land and above. For that, you'll need something like the Kaaz(at the minimum) or the MRT 'unbreakable' dogbox ($5k+ please ).

Case flex is a serious issue with the Scoobs and as Billy said above, engine/tranny mounts help alleviate the problem/keep things aligned, but big torque applications will still cause case flex. They only tranny I have not ever heard of a breakage in is MRT's. Their sales pitch on the dogbox is backed up by numbers, but you pay for that strength...big times.