Scorpion has exactly what I need.
http://www.innov8tivedesigns.com/pro...products_id=79
Turns out the car has 13/38 diffs, so I need a lower KV motor than I thought. On a fully charged 3s pack, with that motor the car will go ~43mph. With 11.1v, the car will go ~37mph. Good enough for me!