Amazon sells armor, vests and helmets.
There has been several innovations in body armor in recent years. Dragon scale styles, ceramic plates and new carbon fiber based armor. Google is a huge rabbit hole if you are interested in body armor. Not all vests are rated the same. Some are good for hand gun calibers only. Some are good up to .308 rifles. Some say that they can even stop a .50bmg (yeah right) but I bet you will still have a very bad day.
I was amazed to discover that body armor is restricted/disallowed for civilians in some places. It is a felony in some cities to own it. Other states require a permit to buy it and wear it. Dumb.
UPDATE: Maryland currently only restricted convicted criminals from possessing body armor. And don't commit a crime wearing any! There is proposed legislation restricting it further. Good catch guys.
--Yet another reason to love Virginia.