Hi, I am in Huntsville Al pretty close to you . I have a C15 and think it is great. I re-learned how to sail on it after some 30 years. There is a great Yahoo group that has tons of information and leads, and is enthusiastic regarding the boat at
http://groups.yahoo.com/group/sailC15/. You can sign up for free.
If you are still looking, I noticed one here:
15' Catalina Coronada 1988 1000.00 OBO. Don't know anything about it, other than they spelled it wrong!
Good Luck