I've lived in West Hartford for most of my life. Golf Club of Avon is a great facility with a good course. If your brother is looking for the best course in the area, I think Hartford Golf Club and Wampanoag are nicer. But in terms of overall facility (Clubhouse, Pool, Dining), Avon is one of the best in the area. One other option is Tumblebrook, but I do not know enough about the course to offer an opinion.
Should your brother decide to settle east of the CT River, have him consider Ellington Ridge. That is one of the better private courses in Hartford County. It's has a good mix of short and long holes, excellent greens, and changes in elevation.