Good to have your company, Semirh. I live in France, too, and there is a problem with geographical sales restrictions on some ebooks. Kindle, by the way, imposes (I think unjustifiably) a near $4 loading on cover price outside the USA, Canada and the UK.
A good option is an ePub-capable reading device, coupled with the excellent but free Calibre Library software so many thousands of us here (and a million others) swear by. You'll find the download here:
http://www.calibre-ebook.com)
You can download it right now and find your way around, even start collecting books, both cheap and paid for. It might well help in your choice of device. I use a Sony and find Sony-Calibre a marriage made in heaven.
Good hunting and very best wishes. Neil
PS: Drop me a line to let me know your preferred genre and I'll happily send you a couple of books as attachments from our DRM-free catalogue in Mobi, ePub and PDF editions to experiment with. You'll catch me on ntmarrATbewrite.net (use the @ sign, of course). N