I want to upgrade my glorious 4890 to play BF3 at 1920x1200 (I dont care about phisX or above screen resolutions) . After reading reviews, benchmarking,.... I'm between two cards: 560ti and the 6950 2 gb. I'm not really sure if it deserves to spend the difference of cost (about 60€); 560 ti around the 185€ and 6950 2gb around 246€ .
Your are correct.You don't need over a 1GB of VRAM unless your using an extreme resolution such as one you would use with Eyefinity or Nvidia surround.For your resolution the 1GB version will do you fine.
As for the GPU I would suggest going with the Asus or MSI cards.They have the best aftermarket coolers out of those.Usually the Twin Frozr pulls lower temps and it's cheaper so you might as well go with that one.