Like bbjd said, Karo is without a doubt the safer choice in this fight.
Karo is a veteran and I admit, Kim has a lot more he needs to learn, like cardio as many of the members here has mentioned.
If Kim's cardio is in the same state as it was in the Brown fight, Kim's in a world of trouble. I'm hoping Kim learned from his previous mistake and has enough gas to perform at his top performance against Karo because he'll need it.
Kim's performance against Brown was very disappointing, apart from the 1st round which was I found very impressive. With that said, I can still see things that Kim needs to work on but he's still young and has lots of time to learn. I do think his fight against Karo is a big step up and he should fight more guys like Yoshiyuki, Goulet, or Carneiro but I think he can give Karo a very good fight, and he most definitely has a chance at winning.
Apart from his cardio, Kim's Jiu Jitsu seemed like it can use some work as well.
Pride of KOREA:
Yoshihiro Akiyama (Choo Sung Hoon)
Denis "The Super Korean" Kang
Yoon Dong Sik
Dong Hyun "Stun Gun" Kim
Bu Kyung Jung
Hong Man "The Techno Goliath" Choi