Well if you want to spent less money you could buy a Xeon 1650 v2 that goes around 100€ on ebay. It's 6 cores 12 threads , turbo 3.5 ghz base , 3.9 ghz turbo boost.
You can easly overclock it to 4.4 , 4.5 . I have one at 4.4ghz with a Hyper Evo 212 really good. You already have everything else...