I think I'd go for #2. Would you want to add more cooling fans to that one too? Corsair is a nice PSU, but at least here, often there are good deals on some of the Antec models. At the same price, in order I'd pick Antec Truepower New > Corsair > Antec Earthwatts; of course the prices may not be the same, but any of those are safe choices, and so is Seasonic.
If you're not in a hurry, it might be good to wait until those new ATI GPUs are out. Even if it doesn't change the one(s) you buy, it will likely cause their price to drop.