I am looking to build a rig with equal or greater performance to my sig rig desktop. Mostly, having problem picking a new graphics card. I want to stick with Nvidia, since the 7 series just came out. What 7 series Nvidia card is going to be equal to or greater than my existing 660TI SLI configuration. Looking to not break the bank. If it is not cost effective, please suggest a decent graphics card that I can use in my current rig, and I will just bring my GPUs over.