If you read everything offered for free by Kurt Harris and Stephen Guyenet, I would recommend none of your listed e-books. If anything, maybe Robb Wolf's book or one of the anthropology books listed by various paleo bloggers (Melissa has a great list on her blog).
Kurt and Stephen are originators of fresh ways at looking at paleo stuff, and I personally would not pay to see those things repackaged. Plus there are so many great paleo recipe sites, that I sort of regret buying Sisson's cookbook (only sort of, because he's a nice guy to support).
If you want free e-books, there's a few of them floating around. A paleohacker med student, who's name I forgot, had a good one a while back. Here is the link: