Re the lighting on the Libra: The attached photo was taken in a room at night, with the only illumination being the Libra's frontlight - how does it look to you?
As for buying books from anywhere, that's the great advantage of Calibre. I just bought a book from Amazon because it was 2-3% cheaper than at Kobo, but after a quick removal of the DRM, I can convert it and load it on to my Libra via Calibre. Kobo's book sales can be quite good too.