There is a site up to capture further requests for information -
http://www.thecoinfoundry.comAs for the terahash calculations... That is up to the miner. The building is what is being set up and conditioned for mining. The output is dependent upon hardware, power stability, heat mitigation, and other variables unique to each mining operation and how they operate and perform.
The practical logistics side of 50MW is complex. I know of 100+MW being sourced right now, but I will tell you from experience that even moving 1MW (400 racks in a traditional data center) takes 1-2 months, even with an army and rock solid facility logistics like at Facebook. So to say that 50MW is is too small is not the case in my perspective. That is 3 months minimum of set up, move in, and optimize from what I have seen in real life. This does not account for production delays, dependencies with contractors to get things ready to operate, or any other variables that lead to setbacks.
There is also the practical financial side of all of this which is that if a mining company signs a lease for 3 years then the financial commitment is $90M USD for rent. Power at 5 cents at capacity is ~$55M for 3 years so to finance a deal at a 50MW scale there needs to be assurances that the $150M nut for the term can be covered. To de-risk that deal then you are talking about a ~$50M deposit. If there is a building owner who will take the risk and not require a massive deposit then the miner will be at risk for losing all of their rigs and physical property if their bills aren't paid. In the world of finance they see this business as having a lot of risk.