I think you could easily get away with standard servo all around, but for a little more rudder authority, maybe go with something a bit more heavy duty. If possible double bevel the edges for the rudder and you will get some knife edge loops in. Due to it's shear size it will not be an ultimate 3d performer, but it will do a great job of all the basic aerobatic maneuvers and you should be able to get SOME of the 3D stuff