I know this is an on road thread, but I used the ACE RC servos referenced by ae_ntc3 above on the throttle and brake of my MBX-5 and Jammin 1/8th scale off road buggies last year and had zero problems with them. They aren't very flashy, but for $85 they are hard to beat. As with all digital servos, make sure you pay close attention to your EPA.