I went with the 6800Gt on the poll, I don't think SLI is available but for a handful of applications, some of them not well done with respect to SLI. If that particular handful is the gaming group of your dreams then SLI makes sense, but that's probably a little more for hard core gamers. I personally don't even see a PCIe board, but PCIe Video cards seem to proliferate the reseller market. Probably best for the future.
I do think the ATI based cards render a better screenshot.