Hey. i live near puerto vallarta, and i can recomend you the guys i always dive with.
the dive shop name is "vallartech" (
http://www.vallartech.com ) they are at "la marina" pretty close to the airport. They offer nitrox and all the dive masters are very experienced technical divers.
Also, you can stay at a very nice hotel, "flamingos" just 200 mts far from the dive boat... they give you special price if you`re diving with vallartech. ask them. now is a good time for whales and giant mantas, but i think in february the water is chilly, ask them for this too.
For dive sites to go in puerto vallarta, i personally like "el chimo" and "el morro", this places are for advanced divers, also you can go to "marietas islands" or " los arcos" sites and "bajo de cristo".
But the best place to dive, from puerto vallarta, is "el banco" since is the farest place to go, (3 - 4 hours) they only go there if there are 4 divers, but is really nice place. its also recomended for advanced, nitrox divers, since the rock starts at 80 ft deep.
Other place i have dove in the area is tehualmixtle, i have an online dive report, unfortunatelly is in spanish, and there you can go only if you carry your gear, and compressor to fill the tanks since there are not dive facilities, maybe a dive trip can be arranged there. there is a sunken boat at 120 ft deep so is for advanced dive, with nitrox. here is the link, at least you can se pictures of the place which is very nice....
http://www.geocities.com/oceanosdivecon/Tehuamixtle02.html
happy dives.... diana