Another option is to U- pin the elevators together for one elevator. However, I have the Edge 540 by Seagull, basically the same model, I used digital servos on mine, I would suggest a high torque on the rudder, or two lesser servo's for a pull pull setup, throttle can be any type, I mounted a micro servo by the firewall for throttle, offset the weight for the servo's in the rear. I have had a heck of a time with cg on my plane, hope your 300 is easier, good luck and good flying!