Here's an interesting little model on servo torque.

http://www.csd.net/~cgadd/eflight/calcs_servo.htm

I threw in some guesses - 50 mph, 30º servo throw & 30º aileron throw for a 24" aileron (two servos) from 1.5" and then to 3". Goes from 9.4 oz ins to 37.6 oz ins of torque. Testing them CA hinges!