When I was in Minnesota recently I visited The Bead Monkey to check out their set-up of printed piddix collage sheets. They carry about 60 different piddix sheets and have a whole section of the store dedicated to them, along with crafty examples and pendant making supplies.
If you're in the Minneapolis/St Paul area it's definitely a fun store to swing by. Or if you're elsewhere, they also have the printed piddix collage sheets available in their web store as well as a great selection of online free tutorials.
If you would like more information about carrying piddix collage sheets in your retail store, send me an email for all the details.