There are many benefits of getting military surplus clothing and equipment from a proper army surplus store. One aspect is that the people that run these stores are specialists in the field of military and army surplus. 

A lot of surplus store owners are also into bushcraft and camping so they will likely have field tested the equipment. You can buy military surplus via https://www.rddusa.com/.

A particular piece of military surplus equipment is good for camping; they will have had first hand experience of using that item of equipment. Surplus stores do tend to stock a lot of clothing and particularly jackets. 

If you are looking for a jacket then you will likely be in luck but if you are wanting something more unusual you will probably have to search a little harder. You may need to go online to find what you are looking for. 

There are specialist stores online that deal with particular items of army surplus. For example there are online stores that only sell combat trousers and others that only sell M65 army jackets.

Generally you will want to choose a military surplus store that specialises in the kind of stuff that you want to buy so that you get the right kind of expertise from the retailer.