Matte Box Rig for film cameras?

[Gabe Agoado]

I've seen a lot of inexpensive matte box rigs on ebay/amazon that run $100-250 (Like this one http://www.amazon.com/FILMCITY-Shoulder ... te+box+rig) and my question is: Would one of these be viable as a multi-purpose rig for film cameras?

The specific cameras I am considering using this with:
Beaulieu 2008s
Fujica ZC 1000
Canon Scoopic MS
Konvas 2M

It is pictured with a shoulder-mount camcorder, however the only photos I can find by actual people are with DSLR's. I'm just skeptical about how it would handle the weight of the heavier cameras like the 2M or Scoopic. I might just buy it for the matte box.