nice usable shack, sure if you don't use your shack it will stay clean, if you use it, it will have a tendency to get messed up. As for power consumption there a gizmo make by fluke that will give you the amp usage of what ever you want. For number figure I run my entire shack on 2 UPS (1100 & 350) and currently consuming around 800 watts. I got 2 servers in there and my full telecom equipments. Like stated previously it not the number of items connected it the number of amps in use.
PS. I have 21 concurrent equipments connected at the moment.