Thanks all for the suggestions. Baja isn't for me (been there before). I did do some research that suggested Lake Chapala might be the best fit for me. Was looking for some confirmation before I specifically asked about it.
Thinking of Ajijic in the next few weeks. One week in hotel to find house/condo/apartment then stay for three months before a longer stint.
Regarding swimming in the lake. Some have suggested no way in older posts. Others have said since April 2010 things have much improved in that way whereas locals have always swam there.