I think your wrong
I don't think it's worth sinking too much time into this retro build
downgrade to 98, pico psu, angle adaptor and a pci 3d card , hopefully the onboard sound is SB compatible and best of both worlds.
the thin clients I have are Yes small but not 100% x86 compatible, the best one i have is a 1ghz via cpu and S3 D3D video loaded with dos / win98, dvi is bugged ( which is a real shame is it limits my monitor choice drastically ) so its VGA output.
it has 1 PCI with an angle adaptor which in there is an aureal vortex 2 with an S2 midi board sitting on the wavetable header. a brilliant win98 / dos setup.
but...
some games crash, doom works great but Warcraft 2 refuses to work and crashes with a general dos4gw protection error, DOTT is unstable and crashes as the cpu is too fast.
although the vortex sound card has very good dos support, it aint no soundblaster and the adlib is well, not so great ( reason for the midi card ).
I did try an IBM true x86 thin client, managed to put a voodoo 1 in it pentium 1 266 ( yes not a typo ), and it ran everything, but it was heavy quite large, no fdd, a pain to boot, each time it insisted to look for the net server and when you forced it to boot legacy was met with a password you had to clear if you haven't used it a few days. ( not the battery )
frustrating,
tried a Mister FPGA for the A0486 core,, too slow.
I've had a couple of small pc's on my eBay watch list but they just don't come down in price, I have VERY limited space ( corner of the kitchen on a desk ) so small is my friend. the reason I use a mist fpga atm for my Amiga and C64 fix
my dream PC is one of either of these.
Unisys CWD-4002 486 DX 2/66 ( will take a DX4 ) pc ( also other brands, like LEO ) with 1 ISA slot for a SB card , FDD and internal HDD, dos dream and smaller than most external cd rom drives
or the Unisys 5xxx range P133 or higher with ISA or PCI slot, depending on the built in sound compatibility it's either a voodoo card or a sb 16
the thing is ,, there not that expensive in the USA and I was about to buy one but sanity kicked in ( not to mention explaining to the Mrs ) why the $150 P&P + another $50 import tax,, Gulp!!
so I've given up atm until either the Mister is fast enough to run quake at a good speed in the A0486 core or someone actually builds a completely separate DOS BOX in hardware. I would buy one for sure!
this look interesting but seems to have stalled and im guessing it's emulation, closed system and not a real x86 in there
https://hothardware.com/news/check-out-pc-classic-99-tiny-dos-games-console