Pocketbook Inkpad 3 checks all the boxes, including text to speech (a few languages out of the box, many more can be installed freely from the official website) and Dropbox, except exporting underlines and notes
http://www.pocketbook-int.com/de/pro...tbook-inkpad-3
On my Pocketbook device (Inkpad 2) I have an It-En dictionary that probably was there out of the box. I don't remember putting it there.
I never used Calibre, but all other Pocketbook users tell it can be used.
If Inkpad 3 is too big or clunky (7.8" screen), a much smaller Touch HD 2 has all the same features
http://www.pocketbook-int.com/de/pro...ook-touch-hd-2