i use the hxt servos from hobbycity....they work just as well as the cheap futaba/hitec/greatplanes/tower servos centering/presicion wise if not better but have significantly more torque which is very noticible
http://hobbycity.com/hobbyking/store/uh_viewItem.asp?idProduct=2&Product_Name=HXT_10kg_ Servo_(metal_gear)_55g_/_10kg_/_.16sec
http://hobbycity.com/hobbyking/store..._bearing_servo

i have over 20 and they all work well