At work we use 220V power supplies with 30A breakers to run 8x GPU rigs in a rackmount scenario. But we also run a farm of hashing nodes. Each rig has 2x power supplies that are redundant to each other. (One PSU is enough to run the entire box but the box will balance the load over the two PSUs).. each PSU shares a circuit with a neighboring hash node in a chain manner. Node A is connected to circuit 1 and 2, Node B is connected to circuit 2 and 3, Node C is connected to circuit 3 and 4 and so on. Probably a little more overkill on power than you need but definitely consider the amperage of the outlets you are going to plug into - 110v maxes out FAST!
Don't cut corners on hardware and it won't cut corners on you. I'd honestly just run reference cards instead of going with the EVGA but that's me. The EVGA's would cause a lot of heating problems due to non-radial airflow in my place of work's scenario. As for PSU: don't go cheap - that is probably one of the most important pieces of your hashing rig as it supplies all the fuel necessary to run the rig. Avoiding cheap doesn't mean you need a 2400 watt power supply, it means you need a trusted name in PSUs. I love Antec for custom "server" builds but I also don't build the rigs at work. Not sure what they are using exactly.
I can't really answer much more as I'm not one of the system's maintainers - just an operator of the front end that we use.
Look up Dustin Heyywood's presentation at DerbyCon from a few years ago. He talks a lot about building and operating a hashing farm for IBM's X-Force pen test team. He gives out a lot of great info that's backed by his experience.
Here's the link with the Iron Geek article and video embedded:
https://www.irongeek.com/i.php?page=vide...in-heywood
Also, at home for my own education, I run hashtopolis for my single GPU rig. It makes managing and building out a hash queue simple and easy, even for one node. I run hashtopolis right on the node.
