You can license books through your Kobo/Borders Desktop software (as you know!).
You can also license books for viewing on
Borders.com
I also like to purchase or license books on
Diesel,
Ebooks.com, and
Fictionwise.
They will all have ebooks in formats the Kobo will find useful. And Fictionwise has plenty of multiformat ebooks without DRM that will work on nearly anything (but jealously guard the files as you would any possession. Tell your friends to buy their own damn books.).