There are also Tera gears for the T-case. One really weak point is the tie-rods but there are also some super beefy replacements that use f-250 ends, etc.
The tie-rods are particularly vulnerable if you crank the torsion bars. Remember when we had High Rider? We once had to change the tie-rod while perched on the waterfall at the beginning.
The most common axles for a solid axle swap are the passenger-side drop Wagoneer axles, although several have been done with a Toy mini-truck axle. The most trick one that I have seen is a three-link using the FJ-80 high pinion axle.