I use "Dr Decal and Mr Hyde", It's Australian based so the wait might be a little while, but they're the only place I've found thus far that offers cheap waterslide paper.
You'll have to scan anything if you wanted to hand draw the design, but once you do just resize it for the paper and print it with either inkjet or laser. Worked like a charm.
Just make sure you get the white background if you're putting them on a dark coloured surface, don't make the mistake I did