Besides the format thing, I think a Kindle 3 may be your best bet. It's one of the cheapest, has a good build and a top-of-the-line Pearl screen, and has one of the longest charge times out there at the moment.
Sonys sound too expensive for you. The nook classic is great and just got an update, but its charge times are always going to be shorter because of its LCD menu screen and though it just added "shelves" its folder system isn't the best yet.
The Kobo could also be good for you, is cheap and offers lots of formats, but for what else you want, I'm not sure how it stacks up honestly.