Whatever way you go, lights should be on and fan(s) should be running before you start spraying. Put a high flow air filter in front of your fan/extractor contraption hood, so as not to allow an ignition source near the vapor. Let the fan be further downstream. You could even create some positive pressure by blocking off the entrance to the room with a big sheet of cardboard or thin plywood with a large hole with a filter over it and have a box fan on hi, blowing on the other side. Clean air pushed in, icky air pushed and pulled out. That's what I would do if I were going "cheap". I think my pulling fan would be an old squirrel cage furnace type blower sitting outside, hooked to the hood inside, via a large flex hose. Luckily though, I have a place to work with great ventilation.
And don't forget a good respirator!