Brushless of course, faster and longer runtimes.

As for batteries, NIMH's will be fine but if you want to save the weight and get more runtime, Lipo's would be good.

On the motor/ESC side of things, a 9XL with a Quark 125B or a Warrior 12020 would do nicely and get that revo goin'! All 3 available from here!