If you setup the servos to fully utilize their output - you can save a lot of money and battery power.
My new pattern setup has ailerons measuring 4" x24 " each and tey are controlled by JR811 servos - a cheap digital.
I have used almost all the JR servos -and fly em in big IMAC models as well . --this new 811 is a bargain!
Extremely accurate and yet are rated at 53 in oz on 4.8 v.
Setup your servos to rotate as much as possible on full rate .
If you are into 3D stuff - then double the servo strength -
By 3D I mean lots of very high full deflection stuff.
For elevators- the small digitals (JR3421) are great .
For rudder - the 8411 w/wo plastic gears is still the best.
The plastic gears are cheap to replace and unless you love to bang the tail on the ground- the best choice.
I run 6V -no reg on this setup.
Engine is ZDZ40 so there is lots of prop blast on the surfaces when needed.