What are your USB settings in the BIOS (XHCI / EHCI)?? What USB port did you use?
Also does anyone know why I would have problems with a GTX 285, GTX 480 or a Titan Black? Is either of those preferred for the install? I'm getting stuck at PCI Configuration begin with all 3 cards and have tried multiple combinations of npci=0x2000, npci=0x300, PCIRootUID=1/0 and -x and nv_disable=1.