I'd say, if you want to learn 3D and then continue flying it without having to change the plane, and don't want to spend lots in the airframe, I'd suggest you get a fun-fly type. Yeah those profiles, I know they are ugly, for me the OMP Edge is the most beatiful, but they will do just about anything you want with a 46 engine, even better with a 50.

Or if you want, you can try the SPA3D for learning then moving onto something better.
If you are going to use 4-strokes, get at least a 70 (OS 70 Surpass or Saito 72), they have much more power than the 52.