Hey Gil,
The main question will be Threadripper or Ryzen. If it's the PC which you also extensively use for active work and you don't plan on adding more GPUs, I'd suggest you go with a Ryzen build. Here's a build that would work well for you:
AMD RYZEN 9 5950X
Noctua NH-U12S SE-AM4
MSI MEG X570 UNIFY or Asus WS x570 ACE
RTX 3090 x2 Blower-style such as the MSI Aero or Gigabyte Blower
G.SKILL Ripjaws V Series 128GB (4 x 32GB) 3600 CL16
Seagate FireCuda 520 M.2 2280 1TB PCIe Gen4 (Cache)
Intel 665p Series M.2 2280 1TB PCIe NVMe 3.0 (OS / Software)
Toshiba HDD 4.0TB 7200 128MB SATA3 3.5 {Projects and backup)
Corsair 1200W PSU
Fractal Design Define 7
