Thanx, in regards to your question, for the time being I'll be using a small floor fan with some of the frame cut away to fit. on low it's about 175 cfm to high is about 300 cfm..
It's a lot easier and cheaper to try out designs and sizes in foamboard than 32 dollars for 1 sheet of ply VS 1 dollar for a sheet of foamboard. Once I've figured out what I need and the venting system, (most likely a downdraft system) then I'll build it in plywood. Allready I've found that the depth is fine but the width is to small and the height is not to bad. i'm spraying about a foot below eye level.