Well, if the Big12 added 4 teams it would only have 14, which would match the BIG and SEC. Yes, the BIG 12 doesn't have 12 teams currently.
Expanded wishlist......UNC, Ga Tech, UConn and really that's it. You could maybe say Cincinnati is a fit. Could extend into the southern footprint with Memphis but I have a feeling they will be snatched up by a major conference soon enough (most likely the Big 12).
SMU likely gets the raw end of the deal when the BIG12 expands to 12 (Houston and Memphis currently have more to offer). If they expand to 14 though they will likely be in. Would like to see Cincy in the Big12 more than the BigTen. Would make it harder for us to recruit against them in Football for sure. If the Big12 added Cincy, SMU, Houston and Memphis, that would be a pretty solid upgrade IMO.