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
Never fear! I will happily spare you the trouble, and take that old thing off your hands - free of charge! ;D
I loved that controller. Best damn gamepad I ever had. It was a sad day when it finally gave in, and broke, last year.