Well there is plenty of info on this model on RCU. You can get away with standard servos with the 61 engine on it, as your load on the surfaces is less. BUT, once you start really throwing the plane around, the loads wil be higher, and may give your servos a hard time.

In my opinion, you will need a high torque servo for the rudder. The others servos do not need to be high end types, but do make sure they are all ball bearing types.

Of course you can also ignore every single word I have just said, and check for yourself whats the best to use. Check out this site, there is a servo calculator there, which should be helpful to you.

http://www.geistware.com/rcmodeling/calculators.htm

Good luck