PC gaming Tech → CPU cooler GPU for a friend.

Long story short. : Friend1 had a rig with a c2d e6600 running at 3.9ghz, with liquid cooling(120mm radiator with one fan, custom loop not all in one like khuler 620), lge 775 pcie 1.1 ddr2 board, 8GB ram, and a 460 oc'd to 470 clock speeds. Friend1 bought a 2500k + lga 1155 pcie 2.0 board, and kept his old stuff. Friend2 bought old stuff, save for water loop and 460, from friend1. Friend2 needs a gpu and a cpu cooler.

Would a 212 evo be enough to get a e6600 to 3.9ghz, or would he need like a NH d-14/h100? Sure its a big oc, but its also a 65w cpu and those tend to run cooler. And whats the best gpu? I've seen some q6600 at 3.2ghz using a 560ti/6950. Sure that has two more cores but this would be 700mhz faster, would those two(or a 7850 since its about the same as a 6950), even with just pcie 1.1, work without the the cpu being a huge bottleneck?