I'm re-modeling a small closet, and would like to use a heavy-duty adjustable shelving system. Something like the RubberMaid Fast-Track or Knape & Vogt 82 series. I'll be building all the shelves, etc myself.

Now here's the question, I'd like to add some cabinet boxes towards the bottom with drawer slides. However, I can't seem to find any support brackets meant for hanging cabinet boxes, only shelves. Are there any suppliers of such beasts anywhere?

Here's an example of what I'm talking about: