I build a vertical flow hood, but if I was to build another one and horizontal, I’d use one of these and a 8” exhaust/blower fan with a controller. Same filter some of the fan filter units use
https://www.amazon.com/gp/aw/d/B00C7WMQTW/ref=ox_sc_saved_image_1?smid=ATVPDKIKX0DER&psc=1