I reccommend this ( http://www.newegg.com/Product/Produc...-655-_-Product
), this is way better than the regular version of the 580 and besides who wants 2x 6970. This has 3 GB of ram and will rip through anything you run on your 30" 2560x1600 monitor. Trust me you will not be disappointed.
2 of these http://www.newegg.com/Product/Produc...-554-_-Product
will cost 679.98, and that's without tax, almost 700 dollars. Wait there is more, you only can use 2 GB of ram on those 2 cards. With any 2 cards in sli or crossfire you get more heat and one of the cards will run more hotter. 2 cards in sli or crossfire will require more wattage as well. Don't let the cheaper card fool you just because it shows similar performance. The reality is that the amd cards run hot just like the nvidia cards. If you get 2 of them, than expect 2x more heat. And if you don't have good airflow in your case than other parts of your pc will also be affected. When you play games on those 2x 6970, they get hot and of course you turn up the fan and that just yields more noise.
My point here is proven. Go with this http://www.newegg.com/Product/Produc...-655-_-Product
and don't look back until Maxwell and Kepler come out.