I'm not gonna lie did not read that whole epic novel.
Sounds like you are going to want a heck of alot more than an i7 quad core. I would look for a used rack mount server from another startup that went under. Assuming you have a 1k usd budget shouldnt be too hard to get dual xeons, 128gb of ram, a significant amount of storage etc.
I picked my virtualization server up for 50 bucks with 64gb of ram, dual 6 core xeons and a nice raid controller.