Caley,
The servos I have in my 1/4 BUSA cub are all Hitec HS-635-HB , they have karbinic gears. At 4.8V they have 69oz-in and at 6V they have 83 oz-in.. I have these at both ailerons , the rudder and I have two installed for the elevator. I would stay away from nylon gears. There is a guy in my club that flies his 1/4 scale with Futaba 3010's, this servo is a HD and has nylon gears. He has never had a problem but for 3 more dollars I would go with Karbonic gears. I mainly fly off the water so I build my planes strong with a little bit larger engines and servos. I hope this helps somewhat.

Wild Bill