No one really fits geographically, B12 schools would make for ridiculous travel costs (and Texas and OU don't want to play second fiddle in a conference anyway) and everyone else within their footprint is either religious, a state school named after their city or academically a joke. P12 will probably need to compromise something if they want to expand.
Also - "The Pac-10 CEOs consider Utah to be a much better academically" - what kind of crack are they smoking? We're twice as highly ranked as Utah, last I checked..