I have 160GB of RAM on my main PC as well as a total of 32 physical cores spread across two processors. It allows me to do all of this along with running 2-3 VMs at the same time as well as play games. I never shut my pc's or laptops off ever unless I'm not going to be using them for an extended period of time (i.e. rigth now I have two desktops, two laptops, and a raspi 3 running right now and they've been on for weeks with the primary laptop being on for the last few months straight).
What you're describing is a workstation, like a Dell Precision (which is what I'm running) or HP Z-station. They allow for goo-gobs of ram (I can go up to 1TB of RAM), and usually two Xeon processors (I can upgrade to a pair of 20 core joints) and they sometimes have enough drive bays to use multiple drives in a RAID array. Slap a good GPU in it and you're good to go with what you want to do.