I read on the Robot Combat forum that someone was selling 3 Victor 883 24 volt ESC. These will handle 60 amps continuous and would be perfect for a tank drive system. http://cgi.ebay.com/Victor-883-24V-Speed-Controller-ESC-Robot-Battlebots_W0QQitemZ130029239950QQihZ003QQcategoryZ71393QQssPageNameZWDVWQQrdZ1QQcmdZViewItem You would need one for each motor.