Arr! Arr! Arr! More Power!
Gerald,
Making this thing work will be interesting. At 1900cfm, you're going to need someplace for makeup air to enter the booth. If you don't have that, you won't be able to see anything since the gloves will be incredibly overinflated! You'll also need to get the women and small children out of the house when you turn it on... Oh, yeah, be sure and tie a rope around your waist.
Another issue revolving around that much makeup air in that small volume will be turbulence. Simply trying to get the paint from the airbrush to the model may be a challenge, and getting it to stick is another story by itself depending on where the makeup air is coming in, and whether or not it can be evenly distributed.
And exhaust ducting will have to be rigid, just so it doesn't collapse from all that negative pressure (I'm assuming the fan is at the end of the exhaust ducting--it looks like a roof or outside wall unit). In addition, moving all that air through a small space could generate some significant static charges. The booth, fan, etc. will have to be well-grounded.
While I don't usually recommend it, putting a rheostat on the fan and dialing it down by as much as 60% or so may be the ticket for good airflow, particularly if you're going to make the booth a downdraft.
Regardless, let me know how it works out...
Gip Winecoff