Variable pitch, disappearing gear etc.. are just differences training. As many hours as the instructor feels neccessary, and a sign-off in the logbook. I did it in my own aircraft (C177).
VP isn't a big deal at all. It's basically a gearbox. Fully fine for take off, a bit less for cruise climb, and a bit less again for cruise. After a couple of hours you'll wonder what all the fuss was about. Same with retractable gear, remember to pull it up, put it down, and how it affects drag and hence speed.
Any suitably qualified instructor can do such training. He doesn't have to be associated with an FTO.