if you are getting plates done make sure you are getting right type of steel a heavy fab shop can contour them easy with a heavy roller and bevel edges to reduce sharp edges that wear a carrier.
a 4×8 sheet of proper steel is about $800 you can get the cutting done and rolling for another $500 in local shop.
you can make composite plates for more protection less spalling fragmentation but it is an art to be practiced before hand make sure if you get a penetrating round that you do not get a bunch of small fibers or particles or infection rate sky rockets.
there are new tech coming out involving liquids/solid.
this idea you get shot and keep on going is nice in theory but getting hit hurts like ****, breaks bones leaves you a drooling fool, getting hit by a rifle/ shot gun can cause internal injuries without a penetration.12 gauge slug is a 2 ton impact imagine 2 burly guys hitting you anywhere with a door buster … you are not getting up any time soon.