i wouldn't bother with the t case gears, just get a marlin dual case adapter and run dual cases. works great in most toys. the 5:29's are made a bit weaker than the lesser ones. i would stick with like, 4:37's and the dual cases.
i just sold off my toyota to buy my kick, it had a 5mge in it with 4:37 gears and welded rear with 35" krawlers. worked pretty well.
just keep in mind when ya get the front axle, may as well do a rebuild on it when you have it out and apart. maybe look into some upgraded birfields, there is a local guy in b.c who makes them.. there called smurfs.
look around for a deal on high steer as well.
just some thoughts.