H87 mainboard is not for K version CPUs and he would need a cpu cooler too if he want to overclock. If he dont want the Xeon cpu can be clocked to 3.7GHz to its turbo with a H87 board.
Please stop spewing such misinformation. Why would he want a server CPU for a gaming PC. Here is the CPU support list for the ASRock H87 Pro4 and it says clearly that the i5 4670K is supported http://www.asrock.com/mb/intel/H87%20Pro4/?cat=CPU
And it is better to get a K series so OP can buy a decent cooler like the 212 Evo later and overclock the CPU to get better performance