There's been no end to suggestions made of books for Suntup to produce editions of (not a bad thing), so here's one more (assuming no one has mentioned this one yet):
Danse Macabre. I think, being nonfiction, it would make an interesting choice that opens up opportunities for unusual additions for artwork (perhaps scans of movie posters; possibilities abound) and new commentary (guest afterword/intro etc.), the dream form of which would, of course, be a true update (not a 2-page thing) from King himself.