Overclockers, Dabs, Ebuyer, Misco, Pixmania, Eclipse Computers and Aria spring to mind.
If you're going to get a card with a reference cooler you might as well get the cheapest you can find and overclock yourself, but that is ONLY my opinion, I've always avoided factory overclocked cards because of the price premium, but then I'm a tightwad and (sometimes terminal) tinkerer
I'd go for the Asus, though, just for the superior cooler.
MSi GTX 670 PE is probably the best card on the market IMO.. Triple Overvoltage means you can overclock this card more than any other card, benchmarks prove that. The Twin Frozr IV cooler also is the quietest out of all of them, and the temps remain pretty low compared to any reference card/board. The Asus DCII is also a great card, and EVGA is really uncreative w/ their cards..