Looked intensely for a place that sold sheet metal to individuals with no luck and gave up.
A few weeks later I started looking again and found this: www.warnersteel.com/index.html Not only do they sell sheet metal to individuals with no minimum order required, they will also cut it into whatever size or even shape, that you need. You could get a large sheet of 16 ga steel or have them cut it into tiny pieces for you for free.
best yet, they are based in indianapolis and are down the street from my house. I've passed by them countless times not realizing. Now I know where to go if I ever try armor making.