Don't ask us what to do, ask yourself what to do. We can not make decisions for you.
Both trucks are fine trucks for wheeling. The toyota IMO is a better platform for upgrading. The ranger, again IMO, is best kept stock or near stock. In the end I would say its going to come down to what your plans are for a rig. If keeping it mildish, the ranger may get the nod. If going for totally built rig, I would probably go with the toyota.
In the end the decision is all up to you.