If I wanted to get into 3D and learn all I could I would get a profile, OMP YAk, MOJO 60, TMP pro Katana. I would fly the snot out of it and while i was flying it I would purchase good 50 cc airframe and engine and build it while flying the profile.

Now if you like to build planes the 50cc That i would start with would be the OMP Hybrid Edge, It has a 92 span and fly's great with a 50cc engine, Mine came in at 16.75 pounds. That is foamy like weight compared to the wing area.