Happy Easter to you, and assuming youre in the armed services, thank you for all you do! Hope youre safe and come home soon!
I might be biased, but i own 2 V8-4th gens and i prefer them to the V6. Both however are Pretty solid (as long as you maintain them!). The V8 does need a timing belt replacement at 90k (as should the water pump be changed and all the fluids and gear lube). The V6 has a chain, but for me, ill make the investment if it means that youre almost getting a new engine sotospeak.
The most common issues on both kinds of Runners are frozen caliper pistons, some potential bubbling/rusting under the weatherstripping, same along the sunroof (moonroof) hardware, the 4-Lo actuator leaking, the V8 has some reports of a cracking of the manifold, the V6 has had reports of headgasket probs.
Again, thanks for all youre doing, get home safe and good luck w the hunt for a 4runner!