I went with a Mamba 5400 and a 7.4v 1900mah lipo. I upped the pinion gear to a 26 tooth and the thing runs great, even with huge 2.2" sand tires. Not extrodinarily fast but has a ton more torque than stock and will run on a single charge anywhere from 40 mins with the throttle pegged to over an hour when I'm being conservative. I just wanted something fun that doesn't break a ton of parts and I definitely have it.

My buddie has a Mamba 8k motor and a 11.4v lipo and it is enourmously faster, he also tears up parts. Can't win with a dead lst in the pits.

You can always just buy one motor, try it out. I don't think the Mamba startup is smooth enough to run a twin setup, maybe another ESC/motor combo would be a better choice. I've also read that even with a better ESC the motors will fight each other but I've never tinkered with a twin brushless setup.

Seems like a lot of useless work when a single 8k Mamba (or any more powerful alternative) and 3s lipo will simply rip nearly every gear to shreds, I agree with GravityJunkie.