I don't know if you are referring to the control panel or the drives, power supplies etc. If it's the control panel, take a look at the ones I did. You can find them through the links in my sig. If you are talking about the drives, etc, then I would use a large metal box, like the ones used for electrical wiring. You can get them in 6x6 size, which is pretty big and can maximize space usage by mounting things to the lid.
You can also use rack mount computer cases. These come a lot of sizes, but are all 19" wide.
HTH,
Chris.
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Dyna Mechtronics 4400C Conversion - CNC bed mill w/toolchanger to Mach3 conversion - http://www.cnczone.com/forums/showthread.php?t=50787