Thanks for this guide. Just knowing this was possible was awesome. I was able to use an Anker USB 3.0 pci-e card. http://www.amazon.com/Anker%C2%AE-Express-Connector-Desktops-Chipset/dp/B005ARQV6U
One thing I ran in to with this on windows 10 is using any sort of USB audio device in this card causes the mouse to freeze. I tried USB speakers, and a USB headset. I tried 2 different logitech mice... 1 wired, 1 wireless and see the same results.
I decided to not have the mouse on the Anker USB card and that fixed it. Was pretty disappointed to see that weird behavior.