Each person is different, so there is no absolutely correct answer. I would suggest that you stay with a foam plane for your aileron trainer because there will undoubtedly be "rough" landings and repairing a foam plane is much easier than repairing a wood frame plane. However, if you enjoy the building aspect of the hobby, then go for a wood frame. The E-flite MiniUltraStick (MUS) is probably the most forgiving plane for you to go with.