Standard servos are fine. That is a hugely overpowered engine for that plane! Enjoy it!
I was going to pick up a Saito 56 for the plane but I want to put a set of floats on it later on so I decided to leave the 72.
JNorton, thanks for the CG measurement. Am I missing something on that page? I can't find the Rascal listed anywhere, I didn't know Great Planes supplied the manuals for Sig kits.