Hello Liam!,
most of the individuals here don't make their own armor, because we all have either found suits that are cast from originals, or the sculptor has taken several years and many thousands of dollars to make a vac forming machine, the bucks, and had to purchase plastic at a very high cost.
most plastic suppliers do not sell small amounts of the high grade plastic you're going to need.
I suggest you look at RS Propmasters, Troopermaster or Authentic Props as likely candidates for accurate armor.
HERE we go again!
making your own armor from your own tools might result in you having to take many years of study to get right?
(unless you are a sculptor by trade.)
Our photo reference section is chock full of detailed photos... enjoy those! and look in the Getting Started section of our site here!
we have a listing of Vetted amor makes and makers.