Why would you want to build a windows machine with the same hardware that windows uses?
That makes no sesne at all.
Lets see, my friend wanted a cheap Mac G5, get the parts all together, plus extra RAM, faster CPU, and I already had a G3 case here at home that I was going to throw away, so I used it instead and kept the cost down.
And lets see, ah, you use windows hardware to use windows on? Thats the same thing that I did with a Mac, So you seem to like to push down on mac no matter what.