As far as I know there are only three breeders that have Charcoal Motleys... I've been looking for a couple of years. Rich has one in the backroom somewhere, but it'll probably cost you an arm and a leg to get it. Michelle of Creatures of the Night and Jeff Mohr both have them, but they aren't parting with any at the moment.
I decided to try to breed my own, but by time I find the "perfect" mate for my Ultramel (100%het for Charcoal & Motley), they will probably be selling them