I will offer my opinion on the coaches you list.
Leach - Yes a top notch offensive mind. Can he recruit is the question. Is a great interview.
Kiffiin - No way in hell do you take him. It is a matter of time until he implodes or explodes. You cannot fix character issues.
Petrino - Again, no way in hell do you take him. See Kiffiin right above.
Sumlin - If your ceiling is 7-8 wins a season, yes. If you want to win the East and Championships, no.
Strong - If he cannot win at Texas, what makes you think he would win at Tennessee? Only if you give an incentive-laden contract with an opt-out clause after 3 years with no money owed.
Miles - Over-the-hill coach still living off the glory days at LSU. Again, he could not win at talent-laden LSU and never developed an even decent offense.
I do not agree that any coach above is head and shoulders above and think several listed are 2nd or 3rd tier right now. Stop living in the football world of 10 years ago because none of these coaches will win the SEC East
Um....not a fan of MIles, and would truly be a desperation hire (still better than Schiano!), but he DID win at LSU. Quite a bit. Just not enough for this spoiled generation of fans. Period, dot.