Moorer. Byrd does not have the power to discourage Moorer. Nor does Byrd have a decided speed advantage like he normally had.
You don't need it. That's been proven so many times. Byrd actually moved around the ring while Moorer likes to just stand in front of you. I believe this fight would be similar to Tua vs Byrd, but Moorer having a much better chance than Tua.