ETSU, they reach elite 8. I think it is possible for them to beat Cincinnati in the first round and the winner of Illinois/Murray St. in the second round.
As for Manhattan, I think they will beat Florida in the first round, but then they have to play a Wake Forest team which in my mind will have a good chance to go to the Final 4 so I dont think Manhattan will have much luck after the first round.
And as for UAB, I dont even think they will be able to get past Washington, let alone Kentucky.
So my sleeper team this year is going to have to be ETSU, although W Michigan may be another possibility.