A suggestion: you're going to need to start planning how you will manage thermals in this thing, it's not something you're going to be able to tack on afterwards. Essentially what your proposing is an insulated box that will cover the miners right? Like a parka in July. You're  probably considering this already, but thought I'd mention it in case you weren't.

As far as thermal management goes it's very doable - here's the approach of one company : http://www.pathfindersystemsdesign.com/wp-content/uploads/2012/06/towercool.pdf it looks fancy, but at the end of the day it's a simple matter of cool air in and hot air hot.