If you have ever checked the price of a boutique Mist Extractor, you might have experienced sticker shock.  This is an affordable design we built in 2017 that works well.  You can modify as needed to fit your needs, or maybe this can provide inspiration to design your own.  The exhaust enclosure was modeled as 16ga sheet metal but any thickness should suffice, the 5.00" outlet could also easily be moved if needed.  I hope this helps!
Links to parts used in this build.
 The Mixed Flow Duct Fan
A link to buy the fan, you could shop around instead.
Flexible Duct Hose
Grease Filter
Worm Drive Clamps