Looking for a good speed controler.

Look at this, with your gearing , 11.1 and a Neu 1515 1.5d, your motor will stay above 30000 rpm and you'll it about 108 km/h.

http://scriptasylum.com/rc_speed/_top_speed.html

Enter all your setup in blank space, for tire diameter, put 4", and in motor choice, select Neu 1515, 1.5d.