IIRC, most of the on-board storage space of the Nook is reserved for books bought from B&N, but since you can put in your own SD card, this may not be much of a problem. Also B&N may not honor the warranty in non-US countries, but you may want to ask this specifically in the B&N forum.
You may also be interested in the Kobo Touch. That is e-ink Pearl and also supports epub.
The technology of e-ink screens hasn't really advanced much in the two or so months since the debut of the Nook STR. Since you prefer epub and don't like the Kindle's UX, I don't really see any reason for you to wait for the next Kindle, as neither of these things will probably drastically in the next version.