I used www.classicchecks.com for mine. I `remember getting like 4 boxes for real cheap. I don't recall exactly how much, but they were the cheapest when I ordered mine. I have dolphins swimming on mine, but they have tons of designs.
If you have Charter One bank you get free checks ALWAYS and they have many cute ones to pick from! You also get points everytime you use your debit card as a credit card and one of the things you can cash your points in for is DISNEY PASSES!!!