Allen and Barbour are the only two on your list worth spit.
I'd vote for Barbour, but have no reason to believe he'd run.
After Allen's-
Support for the McCain amendment
Warner Amendment
Defense of Sheehan deserving an audience
I'd have to hold my nose to vote for him in the General.
I have two issues I place primary importance on. The WOT and the Judiciary. As well, separated from policy issues I place extreme importance on ones character. Allen has flunked the Spine test on the WOT. He hasn't been a leader in the fight over the Judiciary either, the way Chuck has featured his face for the Dems. Character seems okay from what I know.
Rudy has the WOT I'd probably trust him on, but I don't trust him concerning Judges. His character would be subject to attack based on his divorce.