Jam, I don't think that fan will cool that light enough for that hut, IMO, I have a 172 CFM vortex on a 1K air cooled hood and I had to add fart fans to get the temps down, but maybe you'll have better luck. If your not pulling the fan threw a scrubber then the fan will be at max potential and you may pull it off. If you toss the scrubber and use one of those air neutralizers that I posted about in the in door section that you read then you could go without the scrubber.
As for this Hydro hut mini, I would just use the 400 plus on the light and the whole hut as the main exhaust and the Dayton for an active intake, if you try to use both I can imagine that the negative static pressure will want to cave that little guy in, but the Dayton blower will off set some of that pressure and balance out the air flow giving you a good negative pressure, but not over kill.
Adieu.