Just use a matchbox on the elevators and use your flapperon mixxing on your radio. I have a futaba setup and im doing the matchbox system. Works great and alows you to setup each elevator servos seperatlly. Id highly recommend that way. If you use a reversing Y you will loose the ablility to adjust each servo. That plus the flapperon on the showtime is extremely fun if you really want to abuse the plane
If you have any other questions just shout. I love my showtime a lot and im also using the satio 125. Which, by the way is a great powerplant for this bird.