Hi there

I would wait on Ryzen 3xxx benchmarks and then I would decide which one to get, 3600X it will be 6core/12 thread CPU which in Cinebench from leaks looks like is fast as 8700k, 3700X it will be 8core/16 thread, 3800x it will be 8core/16 thread and 3900X it will be 12 core/24 thread abd 3950X it will be 16 core/32 thread

Prices are pretty good 3600 it will cost $199,3600X $249, 3700X $329,3800X $399 and 3900X $499 and 3950X $749 I think

For RAM get CL16 3200mhz and personally would go with at least 32GB, motherboard this again depends on budget but choose good one with good VRM

For GPUs depending on budget again, RTX 2080Ti are monsters in rendering when Turning is supported, but if you are really want use PC for rendering in Poser SuperFly then older GTX1080Ti or GTX1080 etc are good options but fir similar money you can have RTX 2080 or RTX 2070

In LuxMark or LuxRender RTX 2080Ti are great cards and there performance is pretty much great there

SSD or NVMe is must right now there, good case like is Fractal Design Define R6 or Meshify etc are good cases, PSU EVGA G3 are nice PSU and usually they use Seasonic as OEM abd Seasonic are very nice PSU, used one which powered my PC with 4*GPUs all OC and 5960x with 4.7GHz OC

Hope this helps

Thanks, Jura