I think I figured out the fan business. The AC infinity S8 and T8 are the same fan, just the T8 comes with the $100 priced controller 69 pro bundled for $50 more than the S8 with no controller. And the AC infinity S8 is only $10 more than the Vivosun T8(no controller) currently. Whereas the Vivosun S8 and Vivosun T8 are actually different build qualities.
AC also infinity sells 25 feet of 8" duct with clamps for $40. So AC infinity's "fan filter combo kit" is really the same price as buying a fan, filter, and ducting individually from them.