I can see this being a very taijutsu based fight. Orochimaru is about as skilled as Sasuke in kenjutsu. So he'll keep up with Bee for a little while, but without the sharingan, he'll get outmatched. Then he'll be forced back into using shadow snake arms and poison. Which I think he will hit Bee with. I think Orochimaru wins unless Bee enters 8 tailed form fast. If he does, then Orochimaru is in trouble. Orochimaru will have no choice but to bring out the big snakes. Not sure how well Manda or 8-branch jutsu will do against 8 tails.
So.....I give it to Orochimaru. But if Bee goes into 8 tails form fast, then the fight could go either way. But even then, I still see Orochimaru winning. Genius sannin vs skilled comedian jinchuuriki