I know the best GTX 670 for the price I own one, The Gigabyte Windforce 3X GTX 670 2GB version because it has a big fully custom PCB and a jigantic heatsink with 3 custom fans that don't even make noise under full load. With this GTX 670 you will demolish the stock gtx 680
The Gigabyte GTX 670 Windforce 3x is an awesome card. I have two friends who own one and they love theirs. Too bad they don't do any overclocking like I do, hehe. Personally, I went fot the Asus DirectCu II version sice it's a little quieter and cooler then the Gigabyte version but still, the Gigbayte is probably the best all around GTX 670. The fact that it uses a GTX 680 PCB with extra power to feed the GPU makes it great for the overclocking you want to do, even if it's just a minor one. Hope you're happy with whatever you decide on!