Make it huge, make it accessible, make it distinct (I think all the modern stadiums prefer a bowl so the rectangle facade is probably gone but you can hopefully save some of the old style at least). Make sure the catering is great, the seats are comfortable with legroom (but still right by the pitch), and the other “little” things are taken care of.
according to the Athletic, our budget is £2 billion. By contrast, SoFi (which apparently Ratcliffe wants to emulate) cost $5.5 billion between 2016 to 2021. Not sure how we can spend half the money to get something of a similar standard. That makes me nervous.