I'm in. I'll use a GTX 680, although I have been eying the 7970 Matrix Platinum, damn that's a nice piece of hardware.
Viz,
Since you asked
You pick the bench, Vantage, 3D11, Heaven, I believe you should have the competition with one GPU only with some parameters like you did in Pi, I have learned the value of the pcie lane switches on the ROG boards, then towards the end have a bonus run for all out anything goes so we can contribute to global warming
And thanks for taking you personal time to put on these competitions, although I didn't participate in the Pi challenge, I still watched and learned a lot.