IMO 200 oz for a buggy and 250 for a truggy is the min for steering, but servos these days blow that out of the water. My fav servos are the KO RSX power servos 436oz @ .11 sec. Way overkill but by far the smoothest servo I have ever seen. For throttle I like somewhere around 180oz or higher I have used less but I think they struggle with the brakes. The Savox 1268 are a descent choice too great price and good #'s 361oz @ .11 sec. I am using these in a MBX6T on both steering and throttle and they are good so far. Also you cant go wrong with Hitec's personally I would use 7950 or 7955 and I would stay away from the 7940's I dont think they are quite up to the task of 1/8 scale long term.