Servos are more attractive as well from the point of view of avoiding the stepped-nature of the motor spindle rotation - put any mass away from the centre of rotation and it's going to be evident on camera that the head with be bouncing around each step position. Plus the built in gearing of the servo gives obvious benefit in loading. If the radio system removes the need for the Arduino - a good thing (you can, of course, use the ardi to drive the servo as well), but if the goal is simply to have a remote radio providing the drive and head motion, then a RC solution could work well