[unkown-unknowns]

Someone in the comments linked a cheaper alternative: http://abusemark.com/store/index.php?main_page=product_info&...

Seems that the firmware for this cheaper alternative is not open source but from what I gather it doesn't need any proprietary drivers on Linux. Since it interfaces over Display Port and USB I don't think it should be able to do anything nasty so the closed firmware doesn't matter much IMO.

It's not clear to me whether either of the one you linked and the one I linked has touch support.