Assuming you're using modified 360 servos to drive the dozer? the firgelli actuators have their own esc built in, then probably all that's needed is a BEC from Castle Creations to power everything through the rx. Then you're not limited to using just the rx 4.8v batt, but rather 6,7,10 cell or 1,2,3,4,ect lipo of any amp size.
http://store.rc4wd.com/Castle-Creati...or_p_2253.html
http://store.rc4wd.com/Castle-Creati...or_p_3536.html
2nd one is programmable to set limits for voltage & amperage outputs via your computer with this device.
http://store.rc4wd.com/Castle-Creati...t-_p_1348.html