My 30% Lanier Edge uses a 705BB servo for the rudder. i used a bellcrank system, and it'll knife edge loop no trouble. I'll reserve my decision to use 1 or 2 servos for the rudder and ailerons until I decide what powerplant I might drop in. I have a ZDZ 50 NG on route, but I may steal a spare ZDZ 80 for it. The dimensions of the 87" Edge are very close to my 30% 90" Edge, and I use a ZDZ 80 in it...

Peter