Nami vs Devon feels obligatory
Jinbei vs Burguess works since both are the helmsmen. But I think Burguess could also either be an opponent for Franky, since both are cyborgs now, but that's only if Burguess's enhancements go beyond his face. If not, then its all Jinbei
Robin vs Pizarro makes sense since both can grow multiple limbs, and now both have the means to manifest as bigger versions of themselves.
Sanji vs Lafitte could work, but I think only character-wise, since both like to work behind the scenes, at least initially, and Lafitte seems to hold a lot of influence, but not as much as Shiryu and Aokiji seem to hold. Plus, he has kind of an okama-vibe which could rile up Sanji. Otherwise, Lafitte looks like he's more of a Brook opponent.
For me it's:
Decided:
Luffy vs Blackbeard
Zoro vs Shiryu
Nami Zeus vs Devon
Usopp vs Van Auger
Chopper vs Doc Q
Robin vs Pizarro
Brook vs Lafitte
Jinbei vs Burguess
Undecided:
Sanji vs either Vasco Shot or Kuzan. Vasco Shot because Sanji deals with food while Vasco deals with liquor, both are the perverts of their crews, and both can use fire now. Kuzan because it's Fire and Ice, which is a good match-up, and Sanji hates Aokiji for what he did to Robin after the Davy Back Fight. I also think he could end up fighting Pizarro, since both are from North Blue and both are royalty from there, suggesting a link between the Avalos and the Vinsmokes.
Franky vs either San Juan Wolf or Buguess if the latter has more cybernetics.
Loki vs Sanjuan Wolf, Kuzan, or Burguess.
And finally, Vivi and Carrot vs Stronger and Caribou because
@CoC: Color of Clowns's theory drove me insane.