I don't see Zoro fighting Kizaru. There would be no point in restricting Kizaru to just a sword fight.
As of now I would still say that Fujitora is the better fit. Zoro should become WSS before or simultaneously with Luffy becoming Pirate King so such a fight with Fuji would be after Mihawk has already been defeated. He doesn't really fit well in the final war, and the idea it would be an epilogue fight is just funny.
Who says that Kizaru will be restricted to something in particular? If this fight happens with them being in opposite sides, both men will go all out. Restricting Borsalino to swordmanship because he is fighting Zoro doesn't make any sense.
The main problem with Fuji is that, by the time of the Final War, I don't really see him fighting for the WG, if what the story has shown us about this man and his character so far is any indication to how things could develop in the future. I don't think he will be an opponent that the straw hats will have to overcome.
Those are the main arguments I have seen for Zoro vs Kizaru :
•There is a consistent trend in the manga of Kizaru being put against vice captains/right hands/first mates : Rayleigh, Marco, Benn Beckman. Be it clashes, interactions etc.
•Kizaru being the one to almost kill Zoro until Ray saved him. This event doesn't hold the emotional weight of the interactions between Luffy and Akainu but it's still pretty significant.
I have also seen some interpretations of the Akainu/Kizaru dynamic being similar to that of a captain/vice captain, even if such terms obviously doesn't exist in the marines. With Kizaru seemigly being the closest to Akainu, a sort of right hand man and also being older than him.
I think that Kizaru fighting Zoro would fit very well while Luffy takes on Akainu.