I would like to know which fonts work best for armor bumper codes and for stenciling names on ruck sacks or other bags. I hope this makes sense. Anyway, if anyone could tell me what fonts to use and what font size is correct for these it would be a huge help.

Go to www.acidfonts.com and you should be able to find something to match. They have a pretty decent search engine. If you enter in Stencil, Sand, or Military you should get something that will work out.

Andrew,
Tlai ( http://www.tlai.com) has got a font called MD Military Stencil that should solve your problem. I think you can also download a demo version.
Ciao