i had some of these on my emaxx, and they worked real well. totally waterproof haha. i ran them suckers sooooo hard, temps musta gone over 220 multiple times, and they still work. for the price, i wouldnt care too much about it. i ran them on two 7 cell packs with no problems.
http://www.allelectronics.com/make-a...MOTOR/-/1.html
http://www.allelectronics.com/make-a...MABUCHI/1.html
http://www.allelectronics.com/make-a...MOTOR/-/1.html