A lot of talk about the Steam Deck on here - where's the GOG Deck?
GOG has not as much money to burn like Valve has.
I'd get a proper handheld anyway, like the Aya Neo. It doesn't run on a Linux-derivate, but on Windows, it offers a much bette compatibility than the Steamdeck.
ps: The GOG verison would be called "Galaxy Flight Deck"