Hi Jess
I've been using a supply air breathing system in my shop for more than 20 years. It is rigged to supply air to my welding helmet, blasting and grinding hoods and most important to my paint masks.
It draws fresh air from out side the shop and feeds it via high speed squirrel cage blower through a 2" pipe to a central point in the shop at the ceiling then via military grade breathing air hose to what ever hood I'm using. This is all home made and works like a dream. It puts enough air through any of the helmets that there is a constant outflow.
Once you have painted with a supply air system you will never want to paint any other way. I have half mask and full face for painting don't really like the full face because I wear glasses. But for certain types of paint I use the full face. Unlike the filter type masks you don't smell paint at all there is no worry about are the filters style good.
I went over to it for health reasons but now that I've been using it all these years I wouldn't think of painting without it. Even painting Por15 with a brush I use it, great at the end of the day to still have your sense of taste and no head ache.
There have been a couple of threads on MLU about this topic which I will try and find.
Added some photos, as you can see it is nothing fancy but it sure works, adding the full hood to the back of the helmets is of course necessary. You would be surprised how much adding a full hood to the back of auto darkening welding hood improves your vision of the weld, no back reflection and with the air stream directed directly down the the inside of the glass it doesn't fog at all.
Cheers Phil