Well, my Frankenstein system is more or less complete. Borrowed 32 GB (out of 64) from a different PC until I see RAM I like at a half-decent price, and I've got an "old" 5700 XT that I received for free sometime back but couldn't use due to its power draw (noting once again that I barely use my GPU, so I may end up going back to my GTX 1060 if I have too many driver problems, especially since a number of cutting-edge emulators, including for the PS3/Wii U/Switch, reportedly play poorly with AMD cards due to said drivers issues, and that's more important to me than anything else). As for my motherboard, I ended up going with a solid but unspectacular choice in the MSI X470 Gaming Max Plus. No bells and whistles, but I wasn't looking for any - just decent VRM/power phase design and all the standard features, and strangely, this board punches a bit above its weight, having tested for better VRM design than many boards literally twice what I paid for it. Didn't go for watercooling (I never overclock and the thought of running liquid in my system is skeevy to me), but the FUMA 2 I got tests just as well as some significantly pricier options and is even quieter.
System is up and running but nothing's formatted yet and it likely won't be for a while because a migration is going to be very difficult. I have not yet decided whether I'll use Windows 7 Ultimate or Windows 10 LTSC. Windows 7 is my preferred option, but man is it getting lean in the years - and it'll take a bit of tinkering to get it to work with the 5000 series CPU. Windows 10 LTSC...is a compromise, but one I've been using for some time with my laptop, I'm not sure if I'm ready to fully jump over yet for my main desktop, though...I wish there was an even further modded version of Windows 10 than LTSC that stripped out some of remaining annoyances and problems to make it a little more hands-off Windows 7-style...perhaps I should do some investigation, since there are certain to be others who feel the same way.
Complete specifications for now:
Case: Fractal Design Meshify C Blackout
PSU: SuperFlower Leadex III Gold 750 W
MB: MSI X470 Gaming Plus Max
CPU: AMD Ryzen 7 5800x
Cooler: Scythe FUMA 2
RAM: 32 GB something or another (temporary) G.Skill 32 GB 3600
GPU: Asus Radeon XT 5700
SSD: TBD, want a 2 TB TLC+DRAM drive, saw one I almost bought yesterday for a great price, but hidden in the details was the fact that it was QLC - no deal!