Controlling a motor over 1A

I just recently received my Stage Zero dolly kit and I am considering buying a higher RPM motor for faster continuous motion shots. For ease of integration I was thinking about purchasing another Dayton Gear Motor (http://www.servocity.com/html/dayton_gear_motors__12v_.html) either the 17RPM or 25RPM model. Both of these motors draw more than 1A at full load and it's my understanding that this is beyond the capacity of the MX2 controller. Would I be risking destroying my MX2 controller by using it to run one of these motors? If so, what are some alternative options? I'm looking for something easy and inexpensive— a simple rheostat would suffice. Any help would be greatly appreciated.

Thanks, Ryan