With 2x 980ti's, the 5820k would be the best bang for your buck. It is significantly cheaper than both the 5930k and 5960x while not sacrificing much in gaming vs those two and not much in workstation capabilities vs the 5930k especially with an overclock. With the money you save, you can get a decent $50 CPU cooler and a bigger SSD, a nicer monitor or whatever else you might want.