Eric

I used 8411 and 8711 in the manual as that is my choice of servo...and also CARF. The model will fly with 8411 all around but the vast majority of Hawks flying in the UK use 8711 on elevator, rudder, 8411 on ailerons and JR579 on steering. Flaps vary, I have spec'd models with 8421, 8411 and 8711 on flaps.
I like the 8711 size case and gears, the ailerons will not take the wider servo...

I have Futaba customers who used their servos, no idea which as we don't sell Futaba

Dave