Fire is what I have. I love it and use it for reading and some silly games when I am bored. As others have said it's more tablet-ish.I see three advertised on Amazon:
Kindle Fire
Kindle paper white
Kindle oasis
As for books, I get a lot of books from bookbub.com that are free or $2 or less. I also use my local libraries and can often borrow books for 2 weeks that way. Never at a loss to find something to read. Let us know what you decide.