Good or bad is impossible to quantify without knowing your intended uses...
Looking it over, I assume 1080p gaming?
As for upgrades/downgrades etc, I'd have some general comments:
1. An i5-7600K and Z270 board won't change pricing much, but are clocked higher - and new tech. Smart buy. (ends up being +$19)
2. The EVGA 500W PSU is not the best, I'd suggest the G550 from SeaSonic or Rosewill Capstone G650 in the same pricerange, and much better quality.
3. Looks like you're going for a Red/Black color scheme?....although there's some white throughout too? You're probably overpaying a little in spots, just to keep the white in there.
4. The 850 Pro isn't bringing a lot to the table that the 850 EVO isn't
5. For the extra $0.10...