Start with the trainer. The PC9 will flip over in an instant which is what you want for sport flying but very scary to watch when you are trying to learn. I found that the theory learned from flying full sized planes didn't help until after I passed my wings test. Then I had enough time to think and do things that the other pilots wouldn't dream of. Such as taking off into the wind and then turning around and landing with the wind. The PC9 will make a great 2nd plane!