take a look at these pictures of a set up from one of the posters on this board. I saved the pictures I liked it so much. It's EXACTLY what you're talking about.
http://boards.cannabis.com/attachmen...2&d=1138896427
http://boards.cannabis.com/attachmen...4&d=1138896427
http://boards.cannabis.com/attachmen...3&d=1138896427