I have 5770 and it can handle almost every games with decent resolution and i game at 1920x1080. 6770 can handle 1080p with avg 30~40 fps in almost games. and in some dx11 titles it performs better than 5770.
for gaming it's HD5770/HD6770<HD6790<HD6850

Best PCIe Card: $100 To $180 : Best Graphics Cards For The Money: February 2012
If 550 wt psu makes u feel "overkill" in this thread, then why u suggested a 850 wt psu in here ?
*www.thinkdigit.com/forum/power-supply-cabinets-mods/153211-psu-1ti-6950-cfx.html
don't u feel it would be "overkill" as well ?? lol ..
Don't feel shocked - which 550W PSU you have recommended ? I can only see 500W and 600W PSU recommended by you
they both have different requirements - dfcols71 ( HD6950 CF thread ) did not mention any budget and he has a SB 2500k which can be OCed very well along with 2x HD6950s - the power consumption will increase a lot when he might OC all of them using more volts so I mentioned what would be best for him.
But here Op has a limited budget of 10k for psu+gpu and OP's cpu even when OCed will require around ~130W and a 450W PSu like cx v2 or VS can deliver ~336W on it's +12v rail - now even if Op adds a 10k or below priced gfx card the power consumption won't be anything close to 300W so what he will do with a 500/600 which will cost him 700 bucks more at-least - so he better invest that extra money to get the most powerful GPUhe can and a suitable PSU to make a perfect balance within his budget.