RE: Servo torque??
The manufacturer of the plane NORMALLY states how many oz torque servos are required. Since they make the plane, they should know what works best in it.
As a GENERAL RULE OF THUMB, standard servos (42 - 46 oz) are fine for general sport flying with a 40 - 60 size plane. Large control surfaces and/or high speeds and/or heavy duty aerobatics (3d type) will USUALLY require higher torque and/or metal gear servos. When you go to 1/4 scale the servo requirements USUALLY go up again.
There are exceptions to everything though. An example, I have a 1/4 scale PacificAero Gee Bee Y with an OS 160FX in it. The manufacturer calls for standard servos on the ailerons and elevator and a minimum of a 75 oz torque on the rudder. This is what I have put in the plane and it flys great - no problems at all.