Per Marty Tirrell.
Gotta say, Gill isn't a bad place to start. Whether or not he ends up here, he's the guy you have to make contact with. I'm not quite sure how he didn't get the Auburn or Syracuse jobs, but I'd imagine if he wants to come to Ames, he'll sure as heck be a top candidate.
By the way, here's my first effort at an ISU coaching interest board.