Getting started, I ran JR 821s. These servos are reasonably priced and readily available. They come standard in lots of JR packages and many sell cheaply on Ebay as people upgrade.
I had these servos in an RC Evolution. The plane served as my son's primary pattern ship for 2 seasons. Then it went to test bed service. It had an OS 160 in it for years both piped and unpiped then went to the Syssa 180 gasser. This plane had well over 600 flights with multiple mishaps and never did I have a problem with any of the 821s, even on the rudder. I am still using them in other planes. Torque is plenty and centering is good.

Hope this helps..
Rick