One thing I would like to add is that you also should keep an eye out for a truck that has already had the engine swapped for a 2.7L out of a modern Tacoma. Jumping to 160HP is a huge improvement for highway use as well as if you run larger tires. The optimal setup then would be a solid axle older truck or 4runner with a 2.7 engine swapped into it.
My build list would be lockers and gearing, and then dual-range. I've seen little 1950s era Jeeps jet up stuff that most people would shake their head at due to having the right setup - so raising the thing or putting bigger tires on it isn't going to do nearly as much as proper gears and diffs and the like.
