Haye should fight Povetkin, that way haye will beat Povetkin and Povetkin will save himself the beating that he will get from Klitschko. Haye meanwhile could move on to bigger fish well Povetkin goes and tries to build his career instead of being destroyed on the biggest stage at the beginning. Povetkin could make that decision himself (not to fight Wlad), but that doesn't seem likely!
Someone like Rahman, Lyakhovich or Briggs. A stationary target who can help him answer some questions about his chin, but who has a big name and is rated much higher than he actually deserves. That said, I wouldn't be surprised if it's against a light hitter with a shaky chin who he can knock out spectacularly.
Whoever said Oliver McCall is simple, worst fight possible for Haye. McCall has never been dropped never mind brutally ko'd, so there's no way Haye would do it.
Haye shouldn't waste any time. I'd say fight an eliminator vs. a very highly ranked HW contender and not in november or something but in a few months, July, August. Don't waste time!
If I were promoting Haye I'd put him in with a couple of decent but light-punching heavyweights and then get him a title shot. Move him up in the rankings. Monte Barrett, Terry Smith, any will do.