Yes, John, there are different sizes, and yes, I would recommend having one in the Sea of Cortez - if for nothing else, setting it at anchor during a blow can really calm the motion. The winds can really pipe up in a hurry, sometimes with literally no warning. Northers, chubascos, elephantes, and psycho winds, are all common names down there.
Any competent sailmaker will be able to assist you with proper size and various options for your boat. I had a very small one made for my 25', yours will likely be the next size up, but they are surprisingly small until the wind starts to blow the tops off the waves, then they seem kinda big.