I wouldn't expect Kindle in Europe any time soon. And currently you buy can Kindle books only with a U.S. credit card. Also, Amazon might claim the most titles but it's not necessarily the books you want (see
here). So if you want the most content, I'd recommend geting either Iliad or Cybook and buying Mobi books from numerous retailers, or a Sony Reader and buying DRM-free or LIT books which can be easily converted.