http://aktivshop.de/catalog/elektrisch-hhenverstellbarer-sch...
The following page has a listing, but I can't say anything about quality/credibility of products/suppliers:
http://www.bueromoebel-werksverkauf.de/inwerk_bm/steh-sitz-t...
If more people are interested I can investigate European options as well.
If you find anything, it would be nice if you could share it with me via the contact form on my site, so I can look into adding it.