Just ordered some of these, http://www.ebay.com/itm/300959220193. I will provide an update when they come in to confirm if they fit.

I planning to try one of these that is left over from my FPGA mining days http://www.blackarrowsoftware.com/store/atx-to-dc-power-adapter.html. It looks like they are still for sale and $20 with a quiet PSU is a lot better than three loud industrial switches.