RE: Piper Cub and engine
With glow power you only need a 4 cell battery pack to power the receiver and servos. An RC car pack is 6 cells and won't be useable. (Too much voltage.)
You or your teacher can buy a standard receiver pack at the hobby shop for about $15.00.
Has your teacher flown RC planes before, or is there someone to fly the plane when it's ready?
Dennis-