I think the machindershop newsgroup/e-mail list/whatever had a ton of Jumbos' sticker sheets archived... Never checked them out, myself, but it's a good place to start. If they're still around.
One approach is if you are skilled in Illustrator, bang out those vectors and use pantone colors. A lot of vinyl places, including fast signs, can handle quite a bit of high quality adhesives work. Some Fast Signs have a new Edge printer than can do solids on clear, including white ink.