For bashing purposes, you can go with the Duratrax Streak speed control. It's about $35 at Tower Hobbies. Tower also sells their own brand of 14 turn mod motors. They're cheap at $20 a pop. Get a couple of those and run them till the bearings fly off.
You can also install another set of brushes that are easier on the comm and wear longer.
There may be a more durable motor, but for $20, it's not a bad deal.
Here are the links.
ESC -
http://www2.towerhobbies.com/cgi-bin...&I=LXD523&P=ML
Motor -
http://www2.towerhobbies.com/cgi-bin...?&I=LXJA78&P=0
Brushes -
http://www2.towerhobbies.com/cgi-bin...&I=LXJY26&P=ML