If you do not plan to overclock, you should just get the Intel i5-7600 (or Intel i5-7500) to save money for the similar performance in non-OC'd at a lower TDP. You also won't be needing that CPU Cooler. The i5-7600 or i5-7500 is best paired with the motherboard you selected, the B250.
If you do plan to overclock, you should change the motherboard to a Z270 to take advantage of that overclockable i5-7600K you initially picked.
For the GPU, the GTX 1070 is geared towards 1440p-resolution/60Hz gaming or 1080p-resolution/120Hz+ gaming. So check if your monitor is one of these. If not, you can save money by choosing an RX 480, a GTX 1060 or an RX 470 instead. Better if you get a model with dual fans (instead of that single-fan GPU used for smaller ITX cases) as you have enough space and airflow in your chosen ATX case.
For the PSU, a good-quality ~500W should be enough. I'd highly recommend getting an EVGA SuperNOVA G3 550W (for 10-year warranty and better quality). You can also get the Seasonic G-550 (5-year warranty and good quality as well). If on a tight budget, the Seasonic M12II-520 is also an option.