I would use the equivalent of the Hitec 525 servos with one elevator servo, one standard servo for flaps flying in a scale manner. If you fly real high speed yank and bank increase torque values. I use 5 cell 1100mah packs with similiar setup. I use hs-225's for light weight even though they cost. I used one HS-545 for flaps in my 18lb 80" Platt Zero with a OS160.