I believe Itachi wins with no intel.
In Taijutsu, Bee would undoubtedly take it with his unorthodox Kenjutsu style, Raiton enhanced blades, Samehada, and speed and strength enhancement in V1.
The only Genjutsu that would be effective in this match-up is Tsukuyomi, but it could very well be the deciding factor. Bee has no knowledge of Sharingan Genjutsu, so he would not go out of his way to avoid eye contact with Itachi, and if someone like Sasuke caught Bee in a Genjutsu, Itachi could easily do it as well.
If Bee goes into a full host transformation, Itachi could combat it with his Susano'o and can most likely seal a large target like the Hachibi with the Totsuka blade.