I stayed at the Mayan Princess in San Pedro in April. They rent condos w/ kitchens, balconies and room for up to 6. They offer a diving package with Amigos del Mar - prices run about $600-$900 per person for a week of diving twice a day (it’s low during hurricane season). They are all boat dives. Amigos is a very well-run business with good dive masters. They’ll rinse your gear and store it over night, and since their dock is right behind the Mayan Princess, it’s definitely the most convenient set-up in San Pedro.
Also, if you have your advanced certification, go check out the Blue Hole. It costs extra but I think it’s worth it.
Finally, take Dramamine or something even if you don’t think you’ll need it. The water is super choppy.