^ I doubt he'll need that! :P
From what I've seen, a 6770(5770) is able to run at 40+ on high settings at 1980x1080p. With no AA of course. And to be honest, the game looks gorgeous on low. Looks better than most FPS today. On medium you wouldnt hit below +45, which is still very smooth. So it's safe to say you wouldnt hit below 50FPS on low at 1980x1080.
Here's a 5770 you can buy on Newegg:http://www.newegg.com/Product/Product.aspx?Item=N82E16814150560
And you'd also need a decent quadcore.