I'd go with a single metal gear servo something with a good amount of torque and speed I use a jr z9100hvs but they don't make them anymore . Jr makes some good servos I have been using them for some time now. For something not as expensive but I heard are great are the savox servos. They are next on my list but my jr's havnt quit yet. Also the badlands are a great tire for what you are looking for .