Here are my thoughts, biased as I am:
The "Insider" (sort of)
1. South Carolina
A former ACC school, perfect geographic and instutional fit. Academically at least on par with NC State and Maryland. Hard feelings with the ACC may have subsided, particularly with Clemson moving to the SEC. Would bring in solid football and tremendous fan support.
A perfect geographic, institutional and academic fit, apart from not being a tidewater/tobacco state. Basketball tradition a plus. Historic SEC affilaition would be the biggest hang-up.
A perfect institutional and academic fit. Has much in common with Wake Forest. A bit of a stretch geographically, but no more so than in the Big 12. Baseball a plus.
A perfect institutional and academic fit. Regionally a bit of a stretch, but again, better than the WAC. Would give Duke a like-minded institution (though smaller) right at the peak academically. Connestions a plus. Athletics a minus.
A perfect geographic and academic fit. A different sort of school, but not ill-suited for the conference. Connections a plus. Athletics a minus.
The biggest stretch. A good but not great academic and institutional fit, but competitive in this area with the middle schools in the conference. Geographically a decent fit, especially depending on realignment. Probably a solid football acquisition, probably competitive in basketball.
Certainly Tulane isn't in the academic class of rice and vandy; of course, baylor isn't in the academic class of tulane (nor are they in the athletic class). The stretch is really baylor - I would suggest smu, tcu and tulsa as at least equally viable academic candidates to baylor (and in the case of at least tcu, superior athletically as well).