I just built a new system with an AMD Threadripper 1950X and 64GB RAM. I don't expect to need 64GB (my old system worked perfectly well with 24GB) but I'll probably use 32GB as a RAM disk. As Rob suggested, PI doesn't need, or take advantage of, a high-end graphics card. It's worth thinking about some fast SSD storage if you haven't already. I got a NVMe drive for the system files and PI swap. I will probably end up with separate NVMe drives when I have some spare cash.
Cheers,
Rick.