I think you miss a LOT space with this design. If you would use a rack adapter you would build in way more miners. At the moment you maybe use 200mm, but colocation racks have space for 750mm depth. Much unused space.
The other thing is... why do you use 3U for PSU? ATX-PSU's are designed especially for 2HU Height. So one would pay for 1HU extra.
in this demo setup you could also mount the PSU Unit and a BitBurner Unit in the front and two BitBurner Units in the back, half the height, same the fun

but what i dont get: why are the plugs for the hoses in front of the Panel, that just makes no sense. Leave the Plugs inside, so you could connect the heatsinks from the units in the front easy with those in the back, if it stays like that it will be a pain in the ass to connect all those hoses.
next point: if you really are going for a datacenter you really should think about power supply redundancy.
you could also use one of those sweet 19" redundant 2kw psus like
http://business.fantec.eu/html/en/2/artId/__1128/gid/__2009020590/article.html