Jim,
You may find suitable rentals anywhere from Chapala to Jocotopec, a total distance of only about 17 miles along the north shore of Lake Chapala. There really isn't a 'Gringo Ghetto' but you will find more expats in Ajijic than in other towns and villages at Lake Chapala. If you wish to be near places to play tennis, there are public courts in Chapala's Parque Cristiania, possibilities in Ajijic and also the club's courts at the Racquet Club Subdivision at San Juan Cosala.