Hi, for a gaming PC you will want a top GPU instead of a top CPU. Usually video-games do not take advantage of Hyperthreading, (which is the main difference between Core i5 and Core i7 CPU's) so I would recommend a nice i5-6600K. You may not wanna overclock now, but games DO get a LOT of juice from high frequency cores, so you may wanna do it in a near future. With the money you save from that CPU exchange, get a better GPU, as I said it is the core of a gaming PC since most of today's technologies reduce CPU use and send all the work directly to the GPU. That said, get a VERY good GPU (like GTX 980, or GTX 1070). Hope I helped, regards :D