For anyone who's interested: There is a brand new, surprisingly cheap and extremely versatile Mattebox available at http://www.geardear.com/

I had the chance to have a look at it for real and ordered a 3 stage model right away.

More than an alternative to Chrosziel and Arri...

See the existing thread on this topic here:

http://www.dvinfo.net/conf/showthread.php?t=70296