Definitely the essentials over the Bible. Pretty assuming that they would want to follow the religions contained in the Bible, what if they wanted to follow Islam or Buddhism? Or how about Vodun?
I would love to tell the people who thought this was a good idea to stop shoving their religion down people's throats. Food and water, fine, but keep your ideals to yourselves.
From the ebook aspect, definitely food and water over a book (sadly) because you can't read when you are dead.