Your Cub won't do 3D very well for a couple reasons. First, and most obvious is the wing dihedral and airfoil. It would be really hard to do a knife edge while the wing is trying to flip itself back upright. Another reason is the wing incidence. The Cubs wing and empenage would fight each other durring high alpha maneuvers.
As far as FMS ... try an extra or an edge ... something that was made to hover.The caps and yaks aren't meant for someone just getting into 3d. Start with something with a thick wing and large control surfaces.