I’m sure your joking but I’ll take you seriously
Not at all doable in the current form factor. You’ve pretty much described a MacPro.
The Mac mini is energy efficient and fanless, and uses CPUs designed for mobile. Intel doesn’t make an 8 or 16 core cpu in a 15W TDP, only quad core. Those parts, just released in 3Q2017, only support 16 GB of LPDDR3 (must be soldered) or 32 GB of DDR4.
A current Intel 8 core (a desktop chip) dissipates 140W and their 16 core—a $1700 part—has a 165W TDP.
btw, don’t forget your 250W GTX 1080 ti


PS Keep your eye out for the new iMac Pro, you’ll love it! Or if you really don’t want a built in screen, the upcoming Mac Pro should float your boat
