Don't get an APU if you intend to do any kind of gaming as said. Not only are the iGPU's in them weak, but they often perform much worse without sufficiently fast DDR3 memory (and they use up some of that memory).
As said something like:
750K
760K
Check PCPARTPICKER and EBay for prices. The 760K seems to be the BEST CPU that motherboard supports.
What COOLER depends on if you plan to overclock, as well as your budget. CRYORIG has a few I could recommend. I'll put in some links below