There may be the possibility that another of Dan's books might be used, but I suspect that there are a lot of different factors that would go into that decision. For one thing, I read somewhere that AMC considers the series to be historical fiction, so if they're going to stay in that vein, then they would have to use one of Dan's novels with an historical basis and an element of horror. This would tend to leave out a fair bit of his material. SONG OF KALI might fit in with that idea, if you consider Calcutta in the 1970s historical enough to satisfy the history angle. I think BLACK HILLS would fit nicely, and so would DROOD.
I'd love to see CARRION COMFORT or SUMMER OF NIGHT done in ten episodes. I suppose you could make an argument that CARRION COMFORT has the WWII angle, and if I remember right there are some instances of the abilities of the villains in the book colliding with actual historical events. SUMMER OF NIGHT wouldn't seem to be quite as easy to justify if history is one of the backbones of their selection criteria. THE CROOK FACTORY would be perfect, historically speaking, but there's no horror angle that I recall.