They are both water release but I give suigetsu the advantage since he is water. He can't be drowned or harmed water and he can't be cut, but we saw when Kakashi fought Zabuza and copied his water attacks Zabuza still had to avoid it.
I think zabuza's gone the way of raditz in dbz, he was tough when we first met him but, as you can see when they brought him back, he's not much anymore, meanwhile suigetsu managed to stand toe to toe with bee for a lil bit, so Suigetsu would win this one.