If you use a WM with virtual desktops you can reduce that to one samsung monitor.
If you use a tiling WM, you can probably reduce that further to an 18" monitor
In general though, it looks good. There isn't anything I can identify there that shouldn't run FreeBSD.
The weak point is probably going to be the motherboard (purely because there is a lot of things on these boards that may or may not play well).
I also personally don't recommend NVidia as it is today. Compatibility is fine with the proprietary driver but if we do keep using it, there is no incentive for NVidia to ever change things and go properly open-source. In my opinion we should always be pushing for this when we can and especially now that AMD is pretty competitive (on FreeBSD where CUDA support is weak anyway) it might be something to consider?