Remember though, close doesn't matter (P2's shop is closer). They pick you up at the hotel's (or, in BB's case, Mata Rocks'--right next door) pier.
Amigos is a class act. They'll rinse and store your gear for you at no charge as well. They're also the oldest, most experienced shop on AC as well as having the biggest boat.
Rumor has it some other shops may rent newer gear but, if you're like me and take your own anyway, that point's moot.
BB is an excellent property. Very clean, an attentive staff, on-site tour/dive booking through Monkey Business and one of the best restaurants on the island on-site.
There are others, but you can't go wrong with those choices.
Not going fishing, are you?