Is there a budget? Because from what you are describing I would think you would rather go to the HEDT platforms rather than mainstream. The 9900K is more geared towards gamers and enthusiasts, not being a workhorse. For that you should instead look at the X299 platform or the AMD Threadripper platform. More so for the memory than the CPU cores as you have more channels and more total RAM storage.
The GPU is also a tad meh? I mean I would be shooting for at least 8GB of VRAM as thats going to be a major resource with large models.