Edo Itachi, Kimono Itachi are 2 decent options. Edo Itachi can let you put Kakuzu to sleep for 3 rounds, then you have Kimono Itachi to make Kakuzu Teams think twice about gaining chakra. Personally, I'd lean towards Kimono Itachi as he can put to sleep a line of units on standard.

You also have Kakashi Beheading Sword which can reduce Kakuzu's Damage by a lot.

Just some options to think about. Of course, none of these ninjas will help you when these people use him at around 300k+ and you're only 200k