Hmm... lesse, well I have no idea how Kakuzu'd respond to poison, but his stone skin should help with the cut-delivered kinds at least. Gas might work, though.
They both operate remote attackers. Kakuzu's generally have higher offense, but Iron Sands is better than any of them, and Sasori's armor body is pretty tough...
This is actually a tough one, I'll have to think about it.
I don't think gimping actually matters too much; Sasori's poison is paralytic anyway, if a wound is caused by that Kakuzu'll still be affecting in subsequent hearts, and Sasori does know the multi-heart thing anyway.
But yea, Kakuzu doesn't need to be gimped, Sasori has a good chance without that, and a definite advantage with.
Kakuzu is extremely strong, and fast for how much strength he has. And his skin technique would make most of his puppets useless, albeit the iron sand one.
Part of Sasori's nice advantage is he can tailor pick what he deploys to his foe.
Also, some of the other puppets showed elemental attacks, so it's not necessarily the only one that'll do. If there's a lightning puppet in his arsenal (which we've only seen part of), then that'll work too.
I don't know who to pick for this matchup. I mean Kakuzu's hearts could blow away Sasori's armor puppet. Although Sasori does have the Third Kazekage which has a pretty huge AoE with its attacks.
Then there's the Kakuzu combo heart thing and Sasori's 100 puppets. My way of thinking might be linear but for now I call a tie.