Excellent flying model...& i love mine, i fitted a HS-645-MG to the elevator & a HS-75BB for the retract servo...rudder is a JR-NES 591.
On first build i had a Fsa110 OS & found it incredibly light & i needed quite a bit of weight up front to balance.
Recently i shed all the weight & fit a heavier SC120 4-stroke...& with a 90 deg manifold the exhaust is inside the cowl.
Ailerons i'm using 645's too. although Jr591's would be perfectly ok.
It flew great with the OS but i wanted that engine fitted in my H9 f4U.
For the price...it cannot be beaten....flys very scale....& although the retracts are not scale they work perfectly well.