My 2 cents:
I use seasonic as well, but would recommend a 750 watt psu minimum (700 for a seasonic). You could save some money by going with an asrock mobo… the tai chi have worked well for me for 8 ryzen builds. An amd gpu will be much easier to run on linux, I refuse to touch nvidia on workstation builds unless there is an application specific need for machine learning and it is not the primary gpu. You should really consider a 12 core ryzen.
Edit: Why no ECC ram?