The GTX 1060 would work with either. The main consideration is: 6500K = if you want to OC; 6500 = if you do not intend to OC.
However, if you are building a new system, the Intel i5's have a poor value as of today. I would highly suggest looking into the Ryzen 5 CPUs, which have better price/performance and better upgradability compared to the i5. Best value would be the Ryzen 5 1600 (3.2GHz - 3.6GHz, 6-core/12-thread, OC'able, 65W, with decent CPU cooler included) which is cheaper by ~$20 compared to the i5-6500K (3.5GHz - 3.9GHz, 4-Core/4-thread, OC'able, 91W TDP, no CPU cooler included) and almost the same price as the i5-6500 (3.2GHz - 3.6GHz, 4-Core/4-thread, non-OC, 65W TDP, with mediocre CPU cooler).