We are only allowed to place rack units in the data center I've tried micro-atx boxen clipped to the side of the racks behind panels and got whacked for that pretty hard. Still saved us like 80 grand in network simulation gear for that project though.

Click to expand...

Awesome.

You could always go to a surplus shop, buy some massive, chunky 4U server box (A Sun Enterprise 420 would do great), empty it out, and stuff it with about a dozen minis, fans, power strips, USB KVM, and an ethernet switch. Do a careful job and no one will be the wiser. ;^)

They also sell shelves specifically for rack-mounting Minis:

http://eshop.macsales.com/item/Macessity/MX4/

http://www.mk1studio.com/www.mk1studio.com/UBL-MMR.html

That might get you into a negotiable "gray area", perhaps. The second shelf in particular looks pretty good, as it secures the components to some extent and provides spaces for the power supplies.