There a few possibilities but I rather expect Lafitte vs Brook because Brook is one of the strongest SHs next the first 4 and BB, Shiryu, Burgess are likely all taken. Lafitte and Pizarro are some of the strongest ones left probably so it may be one of them to tackle Brook and Lafitte's combat style fits Brook's a lot, plus Yamato and the other girls will probably end up facing Catarina, Juan and someone one rather than Lafitte and Chopper - Doc Q most likely. Usopp - Augur.
Sabo vs Burgess (With Sabo kinda on the run right now I think rematch has a chance to occur)
Zoro vs Shiryu
Usopp vs Van Augur
Nami vs Pizarro
Sanji vs Lafitte
Robin vs Devon
Franky vs Wolf
Brook vs Vasco
Jinbe vs Moriah or Whitebeard Jr. (I feel one of these two will join and Moriahs going to be whipped back into shape)
I love Brook, and if Lafitte didn’t get called commander in chief in his vivre card I’d be all for Brook vs Lafitte. I just don’t know if I see it because Lafitte seems so pivotal to the BB Pirates