There is probably a need for this kind of service as the resident expat community ages. There are various considerations which we, as tourist info providers, would not be your best resource for. I would suggest meeting as many expats as possible when you are here. Here are some blogs and websites to introduce you to some people who might be good resources:

http://joannavandergrachtderosado.wordpress.com/

http://debiinmerida.blogspot.com/

http://theresainmerida.blogspot.com/

http://gorbman.com/2011/12/05/first-symposium-of-american-retirees-and-m...

http://www.meridaenglishlibrary.com/

http://www.yolisto.com/