Sorry man. Went back and read my response and it is a little harsh.
With that being said, the only realistic option on this list is Sitaki, and even he's a stretch. He's pretty intrenched at the U. The only realistic options I see at this point are Sitaki, TJ, Lance Reynolds, Nick Howell (not ready yet, but the University and Bronco love him), and the head coach of SUU Ed Lamb...
I would love to see Bevell, but he has no reason to leave the NFL. He'll probably be a head coach in the NFL soon.