Respirator: there are $35 respirators at any home-improvement center. They are designed to prevent the inhalation of overspray and fumes OUTSIDE (or with proper ventilation). Do not rely on anything short of a clean-air delivery system if you plan to spray without adequate ventilation, such as in a sealed paint box. Which, by the way, that "room" sounds like a *very bad idea* to me. If you want a nice, clean job, the most important thing is to keep airborne dust at bay. A clean garage (maybe with newspaper on the walls/floor in the vicinity of the paint area) will be fine. Perhaps run a humidifier for a while before painting if you're super concerned with dust. You will get small dust particles in the paint job anyway, so just sand and fix before clearcoating (if you decide to clearcoat, that is).

Don't know nuthin' about the Husky gun. Sorry.

If you have any more questions, please ask.