Kohler makes a verity nice 3 pane mirror w/ integrated medicine cabinets (Kohler K-99011-NA). You will need to locate your local Kohler dealer or go to their website to order. Depending on the width you need some of the big box home improvement stores carry some options but they are limited in size and also appearance. Good luck w/ your search and on your project!
Arizona Designs Kitchens and Baths