Hello, I am looking to upgrade my rigs GPU to use all three of my monitors for gaming/movies/work/etc. I currently have an Asrock Z77 extreme4 mobo with an i7 2600k CPU and a GTX 570 GPU. I am searching for the best, single, GPU option for three, HDMI, 1080P, 27" monitors. Let's say the spending limit is $600+-$50. Any advice is welcome as I would like to upgrade soon. Thanks.