(you need an account to see links)
This one finds the cheapest ones on the SW but you'll have to go and buy all of them
(you need an account to see links)
While this one will automatically read the books for you
(you need an account to see links)
While this one will buy them for you.
Now, I cannot 100% guarantee these work, as well as the fact that these programs are dated, making the user-agents outdated