I run a MMM w/ 2200kv and 4s. I ran 6s once - over the curb, through the flowers, cartwheeling into the air, and ouch, right into the rear door of my pickup. I think 4s is plenty of power.
The 1:8 buggy tires are mounted via a set of modified Revo hubs and the body is a trimmed ProGraphix Revo.