Many people are fans of military items, be it apparel for hunting, fishing, paintball, airsoft, stage or street or true historical collectibles.  Buying military or military inspired items online can be a confusing proposition.  SC Army Superstore is a great place to start your search.  They sell official military items as well as commercial items to all branches of the US military and Federal Law Enforcemment Agencies.
Most items sold commercially are "mil-spec."  This term is probably the most confusing of all terms associated with military items.  The government has a set of standards on which commercial manufacturers base their products.  These standards are based off a minimum requirement of construction standards and materials.  Some manufacturers meet these standards while others exceed them.  Usually true military items exceed the standards (mil-spec). 
When buying a military item, it is a good idea to contact the seller and find out who makes the item and if it truly meets and exceeds the specifications.  Always buy from a seller who sells to the military.  A company that  sells to the military has to meet Uncle Sam's expectations.  If they can do that, they usually can help you find a durable item that fits your needs.
There are very reputable manuafacturers selling military items commercially.  Tru-spec, Condor, Rothco, Propper are just a few.  You don't have to be jumping out of airplanes or securing our troops to expect the best there is to offer.  You do have to do your research in order to expect the best of your purchase.
Be good! And be good at it!