You can send back the Voyage if you change your mind. Amazon will just repackage it and sell it I believe (and they are already a multimillion-dollar company, Kobo is a good company that needs more money)

. In my opinion, the Kobo is leagues better than the Kindle.
I don't remember how files are managed on the Kindle. I didn't like the cloud storage and the mobi format. Although,
here is something that might help you. According to the article above, the Voyage can't use epub, which is what I mostly use (other than pdf) and which is more widely available.
Here is some quality Dhamma material:
http://www.bps.lk/library_wheels.php (Anything by Nyanatiloka, Nyanaponika, Nyanamoli, Khantipalo, Bhikkhu Bodhi)
Although only in pdf and epub.
http://store.pariyatti.org/Comprehensiv ... _4362.html
http://www.accesstoinsight.org/lib/auth ... on2011.pdf
Two works to study for the rest of your life.
http://www.wisdompubs.org/books/therava ... s_all%3A53 (Copy and paste the URL between
and, the [ ] messes up the BBCode)
The whole Sutta Piṭaka (excluding the Khuddaka Nikāya) in English.
http://www.buddhistelibrary.org/en/disp ... p?pid=1956
Great piece of work by Nyanatiloka. To study ardently.