yeah they're booklets, as for holders I haven't seen anything. although the horizontal card pages might work... two horizontal holders side by side on the page, you could side one end on one side and the other end on the other side.
I store mine in the holders you get to hold 50 cards. They used to have the "snap-tights" but the ones with a lid which slides together are better. Of course, it doesn't really display the card but its good for storage.