I have questions about buying a steam deck for my partner

He plays PC games - will this work for all of those games?

Is it worth splurging on the 1 TB Oled? Is one TB necessary? He plays a lot of games

Any accessories I should get?

Can you link the dock that goes with it and I also read about a 1 TB memory card?

When I buy it from steam’s website, is it okay if I buy it under an account I create or should I sneakily buy it under his account??

I want it to be a surprise!

Ty :)