My husband and I had a casual afternoon wedding when we got married and we bought his suit from Bob's Men's Wear. They had a great variety for him to choose from and they fit the suit perfectly. They also rent tuxedos, if that is what you need. In fact, they were voted the #1 Tuxedo Shop in town.
Bob's Men's Wear has been in the same location for at least the last 20 years (since I've lived in this area) and they're easy to find - at the corner of Lakeview Drive and Kenilworth Boulevard.