What I did was this -
- Lenovo M93P tiny (i7-4785t, 8GB, no GPU: cost $50. I can do upto PS2 at 1.5x, AAA games upto 2014/5 and later indies)
- Offline (once art scrapped by below etc)
- Windows 8.1 install (era appropriate, correct drivers, offline, yadda yadda) + ClassicShell
- Installed Xbox 360 dongle with drivers
- Installed games I wanted / emulators (eg: Dolphin for Wii and GC, PCSX2 for PS2 etc)
- Installed Playnite, set it to launch full screen
- Define scripts / launch conditions (e.g., Getting AntiMicroX to launch when Luanti launches, so that it can be played with controllers instead of keyboard, then shutdown cleanly when return to PlayNite)
- Replaced Explorer.exe as the default shell in Regedit
End result: turn on PC, boots into Windows (in about 2 seconds), launches Playnite (which is full controller / couch mode compatible). Additionally, I can fine tune things like EDID (fine grained control of display modes), ReShade (per game sharpening etc effects), to say nothing of the extra Win programs I can run.
With a bit of skill, you can make games look way better than they have any right to, even on low end hardware. I can dig up some screenshots of Just Cause 2 and FireWatch running in 540p for you if you'd like...you'd be hard pressed to tell it wasn't much higher resolution (viewed on 75" tv from 8 feet away).
Reason I did it this way:
People will tell you Batocera is awesome (and it is) but...there are just some things that run better natively (e.g., Fallout 3 GOG Game of the Year Edition, Just Cause 2 etc). Windows lets you play windows shit natively and the emulation scene (Dolphin, PCSX2 etc) is mature. No need for Wine, Proton blah blah. It just ... runs.
Playnite lets you "hide" games you don't want the kiddies to run. Once you're done with it, you can exit and return to desktop - you have normal PC (though if you do the shell replacement I mentioned, you will have to exit, CTRL-ALT-DEL to get task manager, then run explorer.exe. I only set Playnite as default shell because I wanted ZERO flashes or indication this was a normal windows PC on boot; if a small 2-3 second desktop flash doesn't annoy you, then just set Playnite to launch at start, black screen desktop and go from there. It's much easier for something that is multi-use). Also, because it's just a front end, you should in theory just be able to make a shortcut to "Jellyfin.exe" and launch it as needed from Playnite (haven't explored that myself tho).
PS: Controller-wise: Xbox 360 wireless + dongle for me. 1 $30 dongle can host up to 4 controllers and I already had to controllers :)
PPS: Can I be honest with you? After all this - the kids decided they just prefer the Wii. I had to laugh. Fine...we'll use the Wii (even though I replicated everything on the M93p - INCLUDING upscale, making wii controllers etc work in Dolphin, bought a Dolphin bar etc. I even put the fucking wii music as the background in Playnite!). So much work ... ignored LOL. Eh, I learned a lot doing it :)
PPPS: We have a Google chrome cast with TV dongle attached to the TV, so it can stream Jellyfin from the media server just fine. I really recommend those things (not the new one, the old hockey puck style one) or the off-label one you can get now (ONN I think?). Actually, come to think of it, I'm pretty sure Wii can stream JellyFin now in glorious 480p too lol