That's what I'm saying though, from stock, you're not going to manually achieve much beyond 3.9GHz, and you can achieve that on the stock cooler.
As for your parts list, I'd highly suggest you pick up a 2x4GB 3000MHz configuration opposed to 1x8GB 2666MHz.
Ryzen benefits heavily from both dual-channel and faster DDR4 speeds.
The BR isn't the best PSU in the world, but should be ok for a 2600 + 570.