Two months ago I built my 3rd gamming machine and now I am ready to add more RAM, cooling devices, and another GPU. My new build is as follows:
AMD Phenom II X6 1090T Black Edition Thuban 3.2GHz
ASUS M4A89TD PRO/USB3 AM3 AMD 890FX
ASUS Radeon HD 6950 2GB
CORSAIR CWCH50-1 High Performance CPU Cooler
CORSAIR HX Series CMPSU-850HX 750W
CORSAIR DOMINATOR 4GB DDR3 1600
LITE-ON Black 24X DVD+R 8X DVD+RW 12X DVD+R x2
Western Digital Caviar Black WD1002FAEX 1TB 7200 RPM 64MB
NZXT Phantom Black Steel
Windows 7 64 Ultimate
you will be fine, that corsair is an excellent PSU and your current set up as is won't break 350w during gaming. Plenty of headroom to add another 6950. the 6970 would use a bit more power but still plenty of headroom.
Almost forgot. Do you have any advise on what cooling options I should go with with I CrossFire? This case I have 6 fans inside already, but still would like the best option to keep both cards under 60C when running games. So far I have not seen temps higher than 64C and thats only when I play GTA 4 and Crysis 2. Any other games I throw at this one card only does not push temps above 60C and will like to keep it that way. Also fan speed is set to 40% in CCC and card came OCed to 810MHz and I took it back down to 800MHz which knocked off 2C. Yeah I know..big deal, but hey I play games hard and want to keep system cool at all times :-).
So its between something like this: ZALMAN VF3000N Enter VGA Cooler * http://www.newegg.com/Product/Prod [...] 6835118064 *; or a water cooler that I have no clue about because its very new to me. Any aid on this would be most helpful