Yep, a GTX670 would be almost as fsat as the GTX680, and a fair bit cheaper. With money saved, you can opt for a 120GB SSD for OS, and if your heart's set on the VR, I ain't going to talk you out of it, but use it for storage, it cannot match an SSD in terms of sheer speed and responsiveness. Otherwise, scrap that VR and get a 1TB/2TB WDC Black for storage. You're reusing that HX850W PSU, right? It's powerful emnough that, in the future, should you decide on a 2nd GTX670 for some SLi gaming, that PSU would handle the added load with ease. Might I ask, why nV cards only? Best bang right now, on the higher end scale, is the HD7950 which OC like a mad mutha.....
Rig 2: FX8350 BE | Asus Crosshair V Formula | 16GB RipJawsX 2133mhz | 2x GTX670 SLi | SB X-Fi MB2 | Corsair ForceGT 128GB SSD (OS) | 2TB Hitachi DeskStar + 2x 500GB WDC Blue | Corsair HX1050 | Corsair 650D | 64bit Win7 Pro
Rig 3: C2Q X9650 | Asus Maximus II Formula | 4GB KHX DDR2 8500 | Sapphire HD6990 4GB + MSI HD6970 Lightning | Auzen X-Fi Forte | Corsair Force 3 SSD (OS) | 1.5TB WDC Green + 1TB WDC Black | Seasonic SS-850AT | NZXT Phantom 410 Red | 64bit Win7 HP