I have no idea I will maiden mine tomorrow (sat) I used spectrum digi servos(6Kg) on elevators, rudder and throttle beacuse I had them to hand but the rest are on standard analogue cheapies.
My model has come out at 9llb and I dont feel the flaps or alierons are large enough to give even a standard servo any issues as I doubt the flaps will ever get used and the alieron movements as per the book are miniscule.
I fitted a saito 125A fourstroke in mine and mounted a 2500 sub "c" batt pack on the engine box this gave me a C of G at 65mm measured at the wingtip.

Mick