This one is interesting, I'm on the fence about it though. I have a Hackintosh (i5 3470k,16gb,2X GTX660TI SLI) inside of a G5 case. The interesting thing about the older Mac Pro is they did not really change the design for so many years and you can pickup a empty G5 case for $70-100 on ebay. Only slight modifications are needed to make it work with PC components.