Ok, this is the end. After hours of browsing listings and reading specsheets I'll be going with the og plan of the M12, found an used unlocked threadripper 3945 for half the price of a new 5955.
The M12 board is more flexible in terms of memory as it supports "normal" 2400MHz sticks that aren't a pain in the a.... to find and I already have on my computer, has the right amount of full-length slots and no weird form factor. Plus the Dark Power Pro 12 1500 PSU (not much of a difference in price with the Corsair unit), and the Freezer cooler which I can source locally, I'll most likely undervolt and underclock the CPU anyway.
