Lewis, Wlad are your top picks. Tyson a possibility or any other monster puncher - but he's so damn awkward to land on. Maybe a younger Sanders at the top of his game might have a chance too.
I think Larry Holmes would get the jab going, open up in the later rounds, and find that chin by round 11.
Seriously what is it with Ibeabuchi that several posters think he could do it yet when someone suggests Tyson, they get shot down. Ibeabuchi did well against the small Byrd. He also did well against Tua but then so did Hasim Rahman and he is widely derided on this forum (largely, I suspect, because to do so diminishes Lewis further). As did Oleg Maskaev and David Izon all around the same time. And yet nobody makes them favourites against well established champions. What is it about Ike that people preoclaim him the great could've been? All we know is he never was. I mentioned Tyson earlier as he comes in for so much criticism whereas Ike gets a pass but Tyson achieved more by the time he was 21 than Ibeabuchi did in a career. And Kirk Johnson never sparked Tyson in sparring. I know part of the backlash against Tyson is down to the absurd hype that provides contrast but he really was special for three years and there have been fighters anointed as demigods with reigns of much shorter duration (Foreman, Liston, Holyfield Mk1).