I second the trail edition idea (if within budget).
The Sport has a number of additional features over the SR5 that you might like (or not). I second the 05+ idea as the V6 got the 5spd box and the V8 got a nice bump in power. The 03-04s are nice and probably pretty cheap now.
All 4th Gen 4Runners with 4WD have a center torsen diff that can be locked in 4H or 4L at will. It is useful to have an open center diff in 4L on high traction surfaces where you want to use 4L.
The V8s has 4H unlocked, 4H locked, 4L unlocked and 4L locked modes for the transfer case. The V6 has all of that, but also the option to run in only 2WD mode as well. Seems to be a bit of a gas saver especially with oversize offroad tires.
Personally I like the V8 due to the extra low end grunt (my 4Runner weighs a lot after all the mods). The V6s are nice as well though. Drive both in various conditions and see what you like best. The V6 is a bit better on gas though.
For year and model info see
4Runner