I mean, if geographic areas don't really matter any longer, I'd say make a run at Stanford for the SEC. And add Oregon to get to the 20. Two solid schools with good history, markets and income across the board.
You want to create a super conference of 24 teams? Add:
Clemson (Speaks for itself)
Miami (history, income)
Notre Dame (while the Big 10 is a better fit for them historically and geographically, they would jump at the chance to be in the SEC)
And just because such a conference would be rolling in an Olympic sized pool of cash, add one of the military academies from a prestige point of view. USAFA, Navy or Army adds the educational value as well as the brand recognition... and probably on the same competitive edge as Vandy or Mizzou.