ciao max ! welcome to the forum.
in france also we are really frustrated because there are very few ebooks available outside of public domain (out of copyright) books, but slowly that is changing. in the meantime i read a lot of english books because there is a bigger selection available.
i have a 700 as well ; it's a brilliant device isn't it !
we have a few italian members on the forum so perhaps you can get some info about sources for italian books.
we also have thousands of free ebooks available here (click the "e-books" link in the blue navigation bar at the top of the page) formatted by our members ! be sure to take a look. there might even be some in italian.
and i recommend also
feedbooks ; for the moment, they propose only english, french and spanish language books, but they are constantly developping their offer and i am sure that it is only a matter of time before they will have some italian authors as well. they have classic (public domain) books but also many recent books which are published under a creative commons licence by independent authors.