OK. Are you going to overclock the PC? If not, leave it as it is.
But i5 3570K are on sale at $180 at micro center. Grab it and sell i5 3570 if you overclock.
If you do a lot of modern gaming would STRONGLY recommend getting a bigger HDD; 128GB is not going to last long, most games today are at least 20+ gigs and come out with Gigs worth of patches.