I live on the east coast so can''t help you with sailing schools in that part of the country. I can tell you that the Annapolis Sailing School has a very good program, with branches in FLA and the Caribbean I believe. Or come out to the Chesapeake for a class sometime.
One other suggestion is to look in the ads of the big sailing magazines. Lots of sailing schools advertise there.
As for certification, what do you want to do with your sailing? If it''s totally recreactional, you don''t need anything, although certificates from sailing schools will get you a reduction in your insurance if you buy a boat from some companies. If you want to teach sailing, then you need to get a certificate of some sort. But I do admit I ahve no idea which of the two you mentioned would be better for that purpose.