RE: Engine for plane ?
I suggest a ball bearing 46.
I can recommend (from personal experience), OS 46 FX/AX, Thunder Tiger Pro and Evolution NT. The Thunder Tiger and EVO engines are more reasonable than the OS and given proper care should last just as long. The primary difference between the Thunder Tiger and EVO is:
Thunder Tiger - needle valve on carb (angled back for safety)
EVO - needle valve on rear of engine.