Is PCI-E 3.0 a requirement? No current socket 1155 CPU can use it, and no current GPU can saturate it. I know my z68x-ud7 has the internal USB 3 headers on it, but it is running 2xPCI-E 2.0(x16,x16).
I think the G1 Sniper has PCI-E 3 and usb header. http://www.legitreviews.com/article/1699/1/
The thing you really need to consider is though, if you run a multi gpu setup PCI-E 3.0 runnning x8x8 is at half bandwidth, and as bandwidth is doubled with the jump to PCI-E 3.0, it's essentially PCI-E 2.0 x16x16 so PCI-E 3.0 in that situation is only worthwhile using a single PCI-E 3.0 card. Otherwise your looking for a more expensive mobo that can support x16x16. It really comes down to what GPU are you sticking in this thing?