If I was managing the guy this is what I would do. There are 2 routes he could go by.

#1 Actually test himself as a heavyweight (in no order): Povetkin, Sam Peter, Tomaz Adamek, Eddie Chambers, Cris Arreola, Holyfield, Pianetta, Boytsov

#2 Another easy fight (in no order): Dimitrenko, Krasniqi, Dominick Guinn, Timur Ibragimov, Hasim Rahman, Valuev II, Sergei Lyakhovich, James Toney, Mormeck II, Tarver, Roy Jones Jr. (Sad to say it)