Read read read , but as its your first I wouldn't get bogged down in the minutiae of H vs Noobs. Get a 127 from angus puretime or a 372 from Josh perfectclones and you'll be fine. If you dither about and procrastinate like and old woman you'll just go round in circles. Man up, bite the bullet, pull the trigger and just do it. But ultimately 1.) Its a Rep 2.) Buy what you you like.
I reckon you need a good sized wrist to do the AP , the RO wears bigger Lug to Lug that the ROO. I had a (possibly WM9 version ) RO and found it too big for my wrist it didn't sit well where as the ROO was fine. It was though a mighty fine watch and I was sad to see it go. The PP's I think sit better I had an older cheaper version on Leather and the case wore better IMO.