I've been talking up Kalen DeBoer with my friends for over a year--not only due to his previous experience at Eastern Michigan and Southern Illinois, but even more because of the schemes he and Tedford are running. I think those schemes would be a good fit for Penix (or Tuttle, if it came to that).
People need to understand that IU could hire Mike Leach himself--forget Graham Harrell--and IU still wouldn't be able to run a true Air Raid offense, at least not initially. It would take either Penix or (I expect also) Tuttle some time to adjust, and even more critically, it takes a different kind of line to block that offense. Especially the line splits, which require offensive guards that are at least as good at pass-pro (especially the footwork) as offensive tackles in most other passing offenses are.
It would also take some time to adjust IU's roster via recruiting--true Air Raid offenses don't really use TE's (most of Leach's rosters, at WSU and Tex Tech, didn't even have tight ends) and most, if not all, of the RB's need to have at least some route-running and pass-catching skills.
If Harrell were somehow to come to IU, though, I wouldn't necessarily anticipate a true Air Raid, particularly after having worked with Littrell (who DOES use TE's and places more emphasis on a legit running game than Leach usually does).
I was also intrigued by both of Norvell's main offensive assistants at Memphis, since that offense was more run-oriented than most. But it looks like both of those guys have already moved on to better programs.