I know there's many Android-based e-readers in Europe that fit all your specifications, but I don't have first hand experience with them.
Check out the
Icarus Illumina HD. From the reviews I've seen, the reading experience isn't great, but it runs Android, so you can install other, better reading apps.
If you could live without page turn buttons (I miss them myself, but I get by) there are many nice Kobo readers that fit the rest of your needs. (
search function within the book, highlight word then easily search occurences in the book. I've never tried this, so I'm not sure how good Kobo is at it.)