I just setup a 40% Carden Extra, and I did it without matchboxes the first time. I am using Futaba 9206 servos--2 in each aileron and 2 in each elevator. Because I never could get the servo arms matched perfectly, I always had a little buzzing at extreme throws. With 8411's (which I have on other planes), this would be BAD. So I decided to bite the bullet and get 4 matchboxes (my 2 rudder servos are mixed in the transmitter).

If I were you, I would use 2 matchboxes--one on each aileron. Mount them in the wing root so that you only have 1 extension to plug into the receiver from each wing. You can pick up the matchboxes at RCSuperstore for $44 with free shipping. Not a bad deal! And your 8411's will really be happy.

Ken