93C is waaay too hot for a card to be running while gaming. At that rate, they won't last that long, despite what either Nvidia or ATI say. I've seen too high a failure rate over the years from cards than ran at those kinds of temps on a daily basis.
The best way to keep a card like the 480 cool (aside from H20) is to vent the side of your case and to put some good 120mm fans right there on the side, blowing into the card(s). I've knocked 12-15c off cards before by doing this.
It's not that difficult to modify your side panel and cut two fan ducts if you don't have them. A 120mm hole saw will do it. I did this when I had my 4870X2s in Crossfire. Cut two fan ducts along the bottom of the window right next to the X2s:
Of course I had to put two badass looking skull grills on them, courtesy of MNPCTech. With a system that mean, I just had to.
So those who want to go SLI with these on air can do it. They'll just have to get a little creative with their case.