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
It will be priced as it isnt locking you into a ecosystem like meta, so it will be of course a bit more pricey. ( rumors say roughly 1200$ )