I'll sign up for Judgement, if its still available, or alternatively the Devil.
Just to clarify on medium: you want them to be scanned and printed off on good quality photo paper? I had in mind printing out and hand-coloring, but a bit concerned about the handling qualities of watercolour (a few coats of fixative will help, but...)
chrisam-crystals - let's wait until the deadline Oct 18th until we start considering do more the one card.
euripides - Judgement for you..... I don't think 'photo paper' is quite right, to thin to shuffle with. Card Stock of at least 110lb. Or you could print out on lesser weight and glue to Card Stock.
Whatever medium you do your card in, just remember you will need to produce 22 copies... one card for each of the 22 decks that will be compiled, (one deck for each artist).
I am planning around a particularly beautiful rubber stamp from the Metropolitan Museum of Art. Knowing that this deck has no copyright problems, I'm using that combined with something original.