A digital hs-85 is plenty for any engine size unless the throttle spring is left on but if on such a large plane just use the standard digital's that came with radio or get the
HS-5485 digital standard for about 20-25 dollars digital with 80 ounces of torque.
also on large control surface's counter balance them. this will save a ton on battery power specially with digital servos, then can run a 8711 or HS-m7990TH lol