I find the usual run of the mill PC with a nice power supply, cooling and picking from a list I'll supply to make a fine gaming PC.

-> List at http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107.html

And I'm sure you've read this too:
"Our tests demonstrate fairly little difference between a $225 LGA 1155 Core i5-2500K and a $1000 LGA 2011 Core i7-3960X, even when three-way graphics card configurations are involved. It turns out that memory bandwidth and PCIe throughput don't hold back the performance of existing Sandy Bridge-based machines. "
http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106-4.html

Bob