you need a lot of fast storage ! Photogrammetry eats space like cookies.
Go with at least 3 x 2TB SSD drives and add more USB SSD drives to backup your projects.
And you need NVIDIA graphics card(s)… Start with one (1080Ti…) and build up by buying additionnal ones (you can put at least 3 of them on your motherboard).
Of course, don’t forget all the gears : color charts, bubble levers, tripods, monopods, giant monopods, …
I work in RC from 2016. so I know that fast storage is must have. My concern is what platform to buy - Intel or AMD
9900x with 10c/20t is about 350€ more expensive than 16c/32t 1950x. But, as I mentioned above, I had TR in company where I used to work and i had some stability issues. If intel platform is more stable, little slower and bit expensive, I would go with it. At home I have i5 4440, 16gb of ram, 1060 6gb and I can process 1000+ 24mpx images no problem.
I hope RC dev has a case study showing how much benefits we would be getting on using entry level SSD vs high end SSDs. Seems like RC only utilized a fraction of an SSDs rated speed.
Alignment and reconstruction stage only gets 30MB/s at max.
You should be focusing on getting a good cpu instead.
Ram speed and timing is also not a deciding factor.
For GPU, 1060 or 1070 is good enough, imho.
I have 970 and just recently bought 2070 and I barely felt any improvements on viewport or reconstruction speed.