well, the biggest issue here is actually, YOU, physically getting in and out of the garage while and after painting.... you really don't want to be "hangin out" in there if you can avoid it... do your coating... leave while it flashes.. go back in, rinse, repeat...
plus.. you need to be able to get out at the end.. you can't just throw the door up and leave.. the hood will look like 400 grit sandpaper... you'd have to be able to figure out a way to get out the framed fan/filter/wall thingy.. like a removable panel in the middle between the filters and fan...
when I made one, i ran a good filtered box fan at one end for exhaust, than a double furnace filter at the other for intake... it was as tall as the box fan...