Depending on your budget and overclocking experience, the answers may vary.
I would say something like ASUS B550-E, Ryzen 7 5800X (or 3800X(T) if 5800 is 2 expensiv 4 u) and 2x16Gb kit of RAM.
Now, RAM is the most controversial here because there are many variables. Do you want 3600MHz out of the box or will you get 3200 kit and overclock? Personally, I would recommend Crucial Ballistix, but any CL16 kit will do, generally.