It depends. I don't see Samehada protecting him from V2 Lariats, esp. when Samehada has no chakra ahead of time, so this is assuming the Raikage is BL and would go out assuming his hype.
I would say the Raikage wins. He's far too fast and wouldn't allow Samehada the chance to absorb his chakra whereas Kisame always started his fight in CQC which is suicide when Raikage V2 Shunshin blitzes from the very beginning while Samehada is at it's weakest.
Now, if you had Kisame started Bloodlusted or started using his best techniques, he'd likely win IMO.