Shirew is an obvious winner of the group.
About the one who should advance to the next round I wonder... Bellamy wasn't that strong, but it was only compared to Luffy who took down Croc and who got 100 million bounty on his head, but I do believe that Bellamy would easily take down Sanji and he might have taken even Zoro at that point, but we don't know practically anything about Lafitte. In both of BB's crew's fights (against Ace and Magellan) he (as well as most others) looked close to useless, so I don't really think that it would be a victory for him against Bellamy. So I would go with Bellamy as the second one who should advance to the next round even though I really dislike him.