20 clean portrait sketches from photo to eps

For the website of our university parish we´d like to go from
http://www.khg.or.at/ueber-uns/team
to something like this
https://basecamp.com/3/team with your help. I don´t have a particular style in mind at this point.
People should look relaxed and happy. I´d also like to be able to easily change background colours to mark different rolls in our team, so something like https://twitter.com/jasonfried would be perfekt. Faces should be recognizable in small size (eg social media profile pic on smartphone) and won´t be shown any bigger than a standard post-it.