Here's another thread with the book list in various formats:
https://www.mobileread.com/forums/sho...d.php?t=254119
As I said in that thread, all of the books were originally from Gutenberg, but some books have several versions there to choose from.
At the time, PeterT tried to drum up support for compiling a list of links to current versions of the 100 books, but it never really went anywhere.