Kakuzu faster than Kisame? I'm pretty sure one's speed directly relates to their chakra reserves, so Kisame's the faster of the two.
the thing with the chakra reserves is not quite right, oro said that the kyubi would loose speed after he absorbed the chakra-orbs.
but i agree that kisame is probably faster, kakazu didn't seem to be very fast when we saw him fight.
i think that that depends on many things, both are highly powered by their environment, kakazu by an environment without balks and kisame by water in his environment.
normally i would say that kisame wins, but im not quite sure.