Ricky, first off, the ONLY portfolio (SK book tie in of course) I am aware of that comes with an original piece is the Cycle of the Werewolf Limited edition. It came with with a Wrightson pencil sketch. In fact, IMO Wrightson just knocked off the same pic repeatedly-to my knowledge the sketches are all of the Wolf's head.
Other than that, the Dameron stuff from The Wastelands is a bit wild. I have them all (prints of course) matted and framed and like them, but they certainly don't appeal to all.