If a 45min. drive is still considered close to you, go to Daytona Aquarium in...well, Daytona. The owner has an awesome selection of fish. Particularly if you have a fondness for cichlids. They are his specialty. Another place in Daytona is Amazon Jungle. Amazon is not as big but it has a more diverse selection of fish other than cichlids. I'm sure that someone else will chime in and tell you about good Orlando shops but I don't know any. I only hit Orlando when I take my wife and kids to theme parks.