Depends on what you want to play, you could install windows on the steam deck if you want, if you want to play your steam library games you can get a steam deck, depending on what you want to get, the 512GB have the better screen.
As for other options for PC games, you have portable handheld gaming console such as Aya Neo and Onexplayer, they are way more expensive than your steam deck.
As for other options for PC games, you have portable handheld gaming console such as Aya Neo and Onexplayer, they are way more expensive than your steam deck.