I just bought this board (ECS $30) and also was looking at the i7-4790K . I started to use the website www.cpu-worlds.com where I look at cores/threads/ avx2
i3-4370 = 2/4/yes $150
i5-4590 = 4/4/yes Better priced $155
i7-4770 = 4/8/yes best bet $239 used
i7-4790 = 4/8/yes