For straight unregulated lipo a combo of Hitec 7955 or 7954 for steering and 7940 for throttle/brake cant be beat. For regulated lipo or more of a budget minded standard nimh battery that will still cirtenly hold up to race conditions the ACE 1015 for steering and 1313 for throttle/brake. Both of those brands will give you multiple seasons of running but the ace servos might need a $10 gear set if you abuse them very badly over the course of a year.