I mentioned this in another thread but I would expect Iowa to target Fran/Lick/Alford types, accomplished coaches from mid major schools or Kirk types, accomplished position coaches in the NFL would have low level head coaching experience.
As another poster mentioned, I think Iowa could hire accomplished BCS coaches if they were willing to fork over a big contract. Basically IMO it would go something like this:
Offer 1-1.5 million a year, we're looking at Fran/Lick/Alford/Kirk (pre-Iowa) type candidates (most likely scenario)
Offer 3-5 million a year, looking at Bret Bielema types, accomplished BCS coaches from other middling BCS conference schools
Offer 8 million+ per year, now we're in Stoops category. They're not going to lure a HC away from ND, Michigan, OSU, Oregon, USC, UCLA, Texas, Bama, LSU, or FLA schools, etc because those jobs are too elite. But every other coach is going to take notice and at least pick up the phone and listen.