I have a Dynamo cab, and the sliding shelf was perfect for the computer.
I took the mother board out of the case and mounted it to the shelf with a sheet of tin underneeth (for a common ground). I took out the power supply, attached shelf brackets to it with JB Weld, and attached it to the shelf on top of the tin. For the drives, I had some old 5 1/4" to 3 1/2" drive adapters, so I screwed these to the shelf.
When I hooked it all up and powered it on, there were some annoying vibrations; these were easily fixed with a few dabs of hotmelt glue. The only problem is that the video card and network card aren't supported. It hasn't been a problem so far.
Here's a picture:

This was taken before I finished the cabinet, but it should give you a rough idea. The main thing is to make sure you have a common ground between the parts.