which card should i get?
Sapphire vapor-x 7970:
http://www.amazon.com/gp/product/B008PQAE98/ref=ox_sc_sfl_title_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
Galaxy GTX 680:
http://www.amazon.com/gp/product/B007KFDFW8/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
or PNY GTX 680:
http://www.amazon.com/PNY-GeForce-Graphics-Cards-VCGGTX680XPB/dp/B007KC961K/ref=sr_1_1?ie=UTF8&qid=1374151721&sr=8-1&keywords=pny+680
Sapphire vapor-x 7970:
http://www.amazon.com/gp/product/B008PQAE98/ref=ox_sc_sfl_title_4?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
Galaxy GTX 680:
http://www.amazon.com/gp/product/B007KFDFW8/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=ATVPDKIKX0DER
or PNY GTX 680:
http://www.amazon.com/PNY-GeForce-Graphics-Cards-VCGGTX680XPB/dp/B007KC961K/ref=sr_1_1?ie=UTF8&qid=1374151721&sr=8-1&keywords=pny+680