a few caveats here. first off, if you want more than 1 m.2 drive then this board goes from best b550 to shit b550 cause it drops the gpu to x8 pcie instead of x16. you stick with 1 m.2 and this becomes a 700 euro mobo with the vrms and overclocking capabilities of the x570 xtreme. super kickass as long as you stick to 1 m.2 or dont care about x8 vs x16 lanes (not meaningful with current hardware but likely to be a difference in the next gen or two).
second, you will have to overclock the memory. 4000mhz wont work properly with zen 2 so youll need to let it boot into jedec and then go from there. with the xt you can likely get a high fclk and end up with 3733mhz or 3800mhz which is nice, and these dimms are binned such that you can at least hit 3800c14 which is really fuckin fast lol
that being said, id personally get a cheaper zen 2 and slot in a zen 3 when they hit the markets as they should at least support faster memory and thus be pretty awesome all around. maybe get a 3700x for now, which would be more than adequate, and get whatever kickass zen 3 comes out and take a few euros' loss on the 3700x for resale.
thats about it, pretty solid setup afaik. titanium super flower unit cause efficiency, if you wanna spring for a seasonic that works too. anything in the A tier on the psu tier list would be great, 750-850w is plenty