hey everyone, i currently have the ASUS ENGTX580 DCII and i love the card, and i wanted to eventually go SLI however the card is so damn big that i realized that won't be happening. My question now is should i exchange the GTX 580 for 2x GTX 560's or 570's? or should i keep my GTX 580? And between the 560 and 570 which one is better? Thanks guys!