I want to let you know about a site that I am a part of. It is called Fine Art America where artists, buyers and galleries can go to view and buy art.
What is unique about the site compared to other sites I have used, is that you can look at a piece you're interested in different frames and mats before you buy it! It's very cool. Click on the site and click on a piece that you like. On the right-hand side you will see options for framing and matting and you can choose different colors and styles.
Thanks for looking!