The above translation is way off.
- You could somehow win, but I couldn't stand up to such an opponent for more than a couple of minutes... It's on a completely different level.
- Ah... Either (we) both (he says both/two, meaning him and Kisame) would die, or it would be a draw... The result wouldn't change even if we increased our numbers.
- It was good that we found him at the ramen shop... And he has one of the Legendary Sannin as a lucky charm. That guy (Jiraiya) might be a fair match for the strongest Uchiha from Konoha and the Mist's strongest swordsman.
- Hmm, even so... It's said that every strong man has a weakness...
Kisame and Itachi were talking about the Kyuubi, not Jiraiya. Kisame brings the topic of Jiraiya up later on in the conversation and Itachi acknowledges that he's strong, but he says that he has a weakness. *girls girls girls*
It seems as if Kisame was babbling on about taking the Kyuubi on, that he couldn't do it more than a couple of minutes but Itachi would have a chance. Itachi states that they both wouldn't stand a chance of winning, even if they increased their numbers. Kisame states that it was lucky to find Naruto in the ramen shop but Jiraiya would pose a problem and Itachi just says; girls girls girls.