Get the online for 12 months & expansion pack – this gets you extra tracks etc in Mario kart, online play, plus loads of game boy, snes, nes etc games. Our kids really enjoy playing the old games.
Personally I wouldn’t worry about the oled too much, I try and encourage ours to use it through the tv instead of having their face too close to a small screen.
We have similar setup with Apple TV and HomePods, I believe I can get sound through the HomePods using EARC but I haven’t tried it yet