pc build Multipurpose Gaming/workstation PC

[Stormeye728]

Budget: At most $2,500 US, ideally >$1,000

Country: US

Games, programs or workloads that it will be used for: Heavy niche games with messy code and bad memory allocation, Kerbal Space Program, Minecraft, Blender 3D modelling and animation, writing, web browsing, etc.

Other details: 

Parts I already have: A 1tb hdd that's half full I intend to port, and a few laptop RAM sticks that likely aren't compatible with newer mobos and processors--mostly DDR2 on the very low end.

Peripherals: Well, I intend to fully redesign my gaming setup, as right now it's pretty bad, however the sound system are already pretty much set up, and the keyboard/desk are something I'm custom-making myself from scratch. Definitely at least four monitors, ideally five or six with two or three wireless ones, though.

Other: 120FPS is a must for things like vanilla Minecraft, and it needs to be able to run more heavy stuff at >30 FPS. I can't really tell until I'm getting under 20 FPS, but a lot of games I play actively trigger a degraded mode with decreased graphics at around 30FPS and remove a lot of the fancy particle effects. Watercooling would be nice, but the graphics card cooler would have to be custom-made due to the aesthetics. I'm upgrading from a laptop so old that I can't even find the default specs on the internet, but between manhandling and hardware degradation right now it has 12gb DDR? RAM and an Intel I7-7400u with a partially? functional Nvidia 940MX card.