At this distance, Kisame seems the most-suited for this.
He can easily barf up an entire Ocean and create a Waterdome which allows him to drain each of their chakra.
Raikage's speed is negated due to being unable to use Shunshin.
Killer Bee w/ Bijuu Enhancements is quite mobile with Kisamehada still being quite faster and I'd imagine Raikage's abilities would be useless with Waterdome active and the fact that Killer Bee's ink would blind Raikage though Kisamehada can still sense Bee's chakra and subdue him.
After depleting Bee's chakra, Kisame would likely deplete Raikage's chakra quite easily. Even if Raikage manages to land a powerful blow, it's not going to be comparable to V2 Bee's Lariat and Kisame can still heal from it quite easily using chakra he's absorbed from both of them.
Overall, under these conditions and manga knowledge, Kisame would likely be the victor.