Respirators used for painting should include cartridges to trap organic vapors with a prefilter to snag particulates. The best setup is a silicone rubber half mask equipped with 2 organic vapor cartridges and prefilters. They can normally be found in most hardware stores for about $20-$30. 3M, North, MSA, and others make great respiratory protective devices. If you can't find one at the hardware store, check out a safety supply house near you, or go to www.conney.com. They have a pretty good selection.
As far as facial hair goes, the moustache is acceptable; however, any hair that interferes with the face-to-facepiece seal, including beards, goatees, and long sideburns, should be eliminated prior to spraying. Data on fit testing is pretty much conclusive that facial hair can cause leaks in respirators, which tends to negate why you got one in the first place.
Hope this helps.
BTW, do a forum search on respirators...There are some pretty good threads on the feeding and care of your respirator--not to mention making it fit correctly, as well as when to change your cartridges.
Gip Winecoff