I'm running Trinity Speed Gems Onyx 14T motors on my TXT-1. They're great all around motors, rebuildable, and only 30 bucks a piece at Tower. They're each hooked up to their own Super Rooster, each with their own Panasonic 3000mAh NiMH pack.
I'm running the stock 15T pinion gear, and the truck must do over 25 MPH - yes, I have 9 - 14 pinions on the way from Tower, because the thing just flips over on the lid if I floor it from standing still. This is one powerful freakin truck. If you use the Onyx, just break em in right, and you won't be sorry...
Just hope you can use this post, as your original request is like 2 weeks old... If not, I hope someone can use it
http://www2.towerhobbies.com/cgi-bin/WTI0001P?&I=LXJX17