Hiya,
I would recommend using one standard or better servo up near the CG and use a pushrod with a Y for the elevators. The GeeBee has short moments and you don't want to move weight to the tail. Besides, the mini servos are really meant for mini-planes (park flyers or very small glow) and their gear trains have very small teeth that would strip if subjected to high flight loads. Don't just go by the advertised torque ratings. I have seen several Kyosho GeeBees fly very well with stock setup. My own GeeBee R2 (Paige Aviation kit) was setup with a wire elevator connector with internal control horn and a pushrod to the front mounted servo. GeeBees (at least the R1, R2 and Z) are very sensitive to CG location so check it carefully before flying. Good luck, they are a fantastic sight in the air!