AF, thanks for that very clear picture. Your point about the classroom makes it clear for me in any case, that the right route is the 152 until I've got some idea of what I'm doing, and then move on to the Pitts.
I know it took me a while but thanks to everyone for helping me get there!
Stik, thanks for the reminder. You know that I'm sure now to call him David when I meet him.........the inevitability of it is quite scary!