would do is something similar to what the Jacksonville Jaguars did with their endzone. They had an endzone similar to MU's south endzone. What they did was add a Budzone (which is just a big concession area. On top of that was a nice club/restaurant with some seats in front of that. On top of that was some extra seating (mainly for the superbowl).
I'd do something similar to that, but I would add two big scoreboards in each corner of the South endzone, along with the new concessions, bar/restaurant, and extra seating above.
I think all of that could fit in the south endzone and still not be higher than the east or west side (which would look weird if it was higher).
After that expansion, I would look at adding suites along the East side to make the East and West sides look a little bit more uniform.
After that I would add one or two more seating sections in the North Endzone. I would still leave the rock M, but I would bring the seating around closer to it.
Adding more seats would be nice, but they don't make money unless someone is sitting in them. Clubs, bars, restaurants, stores, etc., will make money AND make the stadium more up-to-date with what is currently out there (at least with regards to NFL teams).
Edit: Here's some pics of what Jacksonville did.
Here's some more pictures. The first few are of the club level. The bottom one is the BudZone which is open for the public.
http://www.floridasound.com/Showcase/AlltelStadium_reno03.htmEdited by BadAsh at 22:38:26 on 03/18/12