when are you there? are you looking to pay someone to do it? or is it more of a "photographer gets a BJ at the end" sort of arrangements? or are you looking for something purely platonic?
I go down to PV every year and from the look of the ads in the gay publications, there must be a lot of photographers who would be willing to take sexy photos. Before you arrive in PV, reach out to one of the gay publications and ask them for recommendations.
Keep in mind that public nudity is not allowed in PV, so any ultra sexy beach photos might need to be done away from the tourist areas.
Questions I would ask a photographer:
Ask to see his portfolio of sexy photos to make sure you are getting what you are looking for.
Set up a price in advance including expenses if there are any.
Ask him for recommendations for the set up for the photos. If he's a good photographer, he will have some ideas.
Make sure you own the images and he is not allowed to use them for a future project he might be contracted for. You probably don't want to have your sexy photos show up in an ad for a sex show. To be on the safe side, I would probably ask him to use a memory card that you supply to put the images on.
I return back to SF on February 2nd.
A few suggestions:
Garbos for a piano bar evening. Usually has great local talent.
Joe Jacks for the whole red snapper. Sit upstairs on the top floor.
MantaMar for the pool / beach club.
For a nice evening, go to The Iguana at Casa Kimberley. Upscale food and beautiful space. No beach clothes!
A few years ago, I went to the Puerto Vallarta Zoo. It's dreadful, but you can pay extra and hold a lion cub, puma cub and jaguar cub. A once in a lifetime experience.
The Puerto Vallarta botanical gardens are beautiful.
Have fun.