Are you upgrading the PSU from an existing one, or choosing parts for a new build?
As a rule of thumb, the processor doesn't matter when choosing a power supply. Any power supply that's enough for whatever graphics card you want to to use, is also enough for your CPU. RX 470 uses about 130W and requires a single PCIe connector so technically even a 350 watt unit would be enough. 500W-650W makes the most sense though: you have the most options, watts per dollar is the highest, and the capacity is high enough for almost any single GPU setup with overclocking.
EVGA 500 BQ is built by Andyson which is merely OK, and covered only by 3 year warranty (5 years would be better, 7-10 years is common among higher end units). I'd probably buy something else. Where are you buying from?