Phoronix article: https://www.phoronix.com/news/Steam-Machines-Frame-2026
Also listed here: https://store.steampowered.com/sale/hardware
Valve has already sent support for the new Steam Controller upstream: https://www.phoronix.com/news/New-Steam-Controller-SDL
Not what you asked for but as someone else who used W11 IOT CachyOS is fantastic. It’s just Arch Linux with really strong gaming first additions.
Haven’t had a hitch.