I know others will disagree, but I think Cowboys Stadium is the most logical place for the state finals. I can't stand Jerry and hate the idea of people paying the parking and food prices, but Reliant isn't feasible for several reasons and frankly, the Alamodome is a HUGE step down from either Cowboys or Reliant. Houston is too much of a burden for West Texas, they would have to change their turf out, and honestly, no one wants to go to Houston who doesn't absolutely have to. Cowboys will never have an issue holding whatever crowds show up, is fairly easy to get to from most of the state, is a much better venue than the Alamodome (and probably better than Reliant), and uses the same turf for the Cowboys themselves as they do for the HS games, so conflicts aren't an issue now that the NFL doesn't play on December Saturdays like they used to.
Use the heck out of Reliant and the Alamodome for earlier rounds. They're good venues and I strongly support basketball going to SA. But Cowboys is the place for the finals until something better comes along.