Nothing beats the bang/buck ratio of used enterprise hardware (always buy new drives though if you care about the data)
https://www.theserverstore.com/ https://www.serversupply.com/ https://www.servermonkey.com/
I’ve bought from all of these in the past, personally I’m a fan of dells but there are arguments for just about any of the major 3 (dell, hp, sueprmicro)
Personally my main server right now is an r630. 96 threads, 768gb of ram. With that many memory channels, not only can you run all of what you listed, you can even do medium-sized inferencing/diffusion if you’re interested in that sort of thing.
A computer scientist, presumably.