Buy a couple hundred dollars of clay, carve and scult your peices, pour plaster to mold them, take plaster mold off. Vasaline the inside of the mold, pour plaster in, take plaster out, you have a 100% copy of the clay sculpter. Vacume form it, paint it.
Molding cost 1000+ dollars to make, so I suggest pepakura if you have 100 dollars to spend, pepakura is where you make the armor from cardstock, yes it has to be cardstock, then you resin it to give it strength, then you fiberglass the inside and it makes it even stronger.
Both come out looking good, but nothing beats the quality of molded armor.