Feel free to PM me, MazMarine
has brokers in three cities -- we worked with the ones in LaPaz (Mike and Shelly are friends as well) but have heard good things about their affiliates in other cities too. They sold our boat.
We bought that boat in 2002 from Nick at what is now Vallarta Yachts
(located in Puerto Vallarta) and we were very pleased in working with him.
There are some other brokers on the Pacific side of Mexico and I don't mean to imply anything against any of them by not including them here -- just that I don't have any knowledge of them.
If you tell the broker what you intend to do and your budget, I think they'll be able to help you find a boat and will tell you honestly the pros and cons of the various ones. They are also very in-tune with the local workers, yards and so on for any work that you decide to have done. There are plenty of good surveyors in Mexico, too, to help you assess a particular boat.