Okay, being absolutely forced to pare down to about one compact car load or around 8 machines, out of what I've got mostly....
5155 PC Portable, with PC Sprint accelerator (to be made) and V20, ATI EGA Wonder, to get mono EGA on internal screen, rig to have a composite out also.
Patriot SL4100 with "Cobalt" class LPX board by IBM Microelectronics with a BL3 Blue Lightning @100, but adjustable multi and freq options, 16MB RAM, 4GB HDD, CF slot CDROM, 1.44. Should do low 286 to 486/66 speeds, maybe squeeze it up to DX2-80. Onboard 5426 or ISA GD5434 VGA.
The mid 90s nostalgia chip Cyrix 5x86 onnnnnn which board? a UMC-VLB was the original, a PCI board would be nice, but might go Asus SV2GX4, Mach64, 16-32MB, will adjust low 486 to low Pentium.
Cyrix MII 366 GP on Lucky Star 5V-1A, 32-64MB, another hugely adjustable board, should get 386 to 233MMXish, plus integer top end closer to PII 400, think I'll go with the Virge GX2 and one of the Voodoo2 12MB, 20GB HDDs
K6-2plus modded to 3, 570, oc to moon on GA-5AX plus multi setting utils, freq adjustments, do 386 to PIII-500 numbers, GF2MX400 plus V2 plus PVR2 128MB
Dual PIII 1100 in Slotkets on P2B-D (If I get it fixed) 512MB this one not very tweakable, but should go down to where K6-2/3plus leaves off, GF3 in the AGP slot, Voodoo3 in a PCI slot, will have to dual monitor or switch. Dual because dual.
Mobile modded TbredB 2400, in VIA KT400A board, 512-1024DDR tuneable down to 300Mhz, up to 2500ish, Radeon 9600Pro AIW, may have Voodoo3 or other PCI secondary.
FX8350 AM3+ board, DDR3, forgot what the hell it is, Asus higher end, wanna get HD7970 seems classic combo, or it gets the R9-390 that's available. 16GB RAM.
That's my big 8 but I might sneak in a shoebox ITX with a C2D quad xeon and GT440 for a bit more XP mid, and a compact 386 build, could prolly hide both of those and the Patriot LPX in a full tower case 🤣
Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.