Hi Jenni, WOW! Those artist certainly have got very unique styles and talent (and good planning as in the case of Kathleen West) I couldn't find anything for these artists that is in cross stitch, but that's not to say it isn't available! Here's a few sites with Fine Artwork converted to cross stitch, and if I do find anything, I'll repost. Carmel p.s. maybe you'll have to get desperate and get a cross stitch programme to make your own patterns!
Let me know if you like this Asian one: http://www.artecy.com/asian-cross-stitch.html Artecy may consider designing one for you too. (I know that they have William Morris, which you didn't want!)