Everyone is correct that the throttle servo is not the place to cheap out. It is not the power that is important, it's the precision and speed. Diablo is correct that a top quality mini servo should be fine for the throttle, even with the spring, whether analog or digital. My favorite happens to be the Multiplex Micro digital(Roger ought to like that). Very fast (.07 transit), excellent precision and power and it weighs about an ounce. I've only used the older Mc2 versions of the servos, I'm not sure how the new ones compare.