If I were to do this:
I'd do it in Douglas County, WA or similar for the cheap power.
http://www.douglaspud.org/Service/2013RatesJanuary12013.aspxYou'll need a /lot/ of power supply and cooling capacity. However, you could probably run ambient air exchange, if you're OK with the building being uninhabitable during the summer months. You'll need a lot of airflow and cooling for this, and the airflow will not be trivial to work out.
Alternately, if you're going big, you could do water cooling with standard cooling towers, but that's really expensive and not at all fast to build out.