gaming 1080 at 60
already have other components
970, cooler, and psu already purchased
Do not want to spend any more money then this -$575ish-...exception being pay a little more for better performance.
PCPartPicker part list / Price breakdown by merchant
That mobo caps the ram speed to 2133, I would spend a little more on a z series board & overclockable i5, that does bust your budget by about ~$20 tho...
But it does give you a ~20% bump over the 6500 as per userbenchmark.
Or you could always drop to 2133 ram and keep that b150 board & the 6500.