Where does one even get a "bulletproof" vest? I've looked at the usual tacticool places; rangerjoes.com, uscav, lapolicegear.com, and various surplus and uniform stores in my area. None of them will sell to a non-LEO or non-Military Procurement officer.
Galls will sell one to you. There's a section on their site that says "by purchasing body armor, you are certifying that you are not a convicted felon, are not a prohibited person, etc etc."