Hello friends! I'm hammering out the details of a little rover im building that will run off an arduino uno, with an duo H-Bridge motor shield. The shield maxes out at about 45 volts and 2 amps (per motor). The bout is going to be relatively small, with tread not wheels for extra adaptability. I will set it up with tank style drive. I want decent torque to navigate the home, speed isnt really a priority. Whats a good balanced motor for me??? Thanks for your time and responses!
Tank style drive is extremely NON efficient .... You will need to grab few details about your robot and calculate the motors 
Yeah it's true-- Weight is also a big issue. I'm using an RC car for my platform for my UGV, and it works amazingly--if you want tank treds for the ability to turn 180 degrees in place, I'd use the sparkfun wild thumper 6 wheel drive chassis. It's also just plain awesome