Going to an auto would be my choice too....it's probably so much effort and expense to convert that I would think it would be 'less trouble' to just buy another truck with an auto and switch your preferred stuff over to it...like maybe the custom stereo etc.
Now with the auto you could run let's say, as an example, 33x10.50 tires with 529 gears and probably have a nice comfortable cruiser on the highway and plenty of low speed capability offroad (without any additional transfercase gear changes).
I have run 571 gears in my 1987 22RE Runner auto with 33x10.50 tires....maybe a little too revvy on the highway for some (75 real mph at 3400) but it had plenty of offroad torque and slow speed capability.
ZUK