I use the xxxl hood, also, with the 6" port. I also have a 1000w (+ turbo charged 1100w) ballast, which both are definitely overkill in my 4x2 tent.
BUT! The nice thing about buying more than I needed, was that I don't need to upgrade when I get a bigger space. Just food for thought, I'm sure there are a lot of other options that are a lot more cost effective.
But if you ask me, if there's one thing that you want PLENTY of, its light. It will only translate to bigger, denser buds. The my ballast runs at 400, 600, 1000, or 1100 and I've been running it at 1000 with no problems, but I do have air conditioned intake.