The people you are looking for are the types that are well known and respected within the academic community. ENT is a small field so people in academics typically know each other to some degree, at least regionally.
Any chairman should satisfy the "big wig" requirement. Other than that, the easiest thing to do is open up any of the main journals. In the first few pages there should be a listing of people on the board of editors. That's a fair place to start.
It's extremely helpful to have a LOR from someone that is well connected, personally known by other people you will interview with, and respected. However, it's even better if that letter writer actually knows you and can write more than the standard cookie cutter letter after working with you for a day or two.