Plate sizing: How to do it?

So I'm 6'4" tall, weight 205 pounds, have a 35" waist and have a 44" chest. I have seen 10"x12" plates, and though they'll cover exactly the vitals in the Steve Fisher zone, they are a little small on me. So the question is: How do I correctly size plates for my body? Additional considerations:

1. I'm getting the Velocity/Mayflower LPAC carrier with Velocity's VS-63A1 soft armor.
2. I am looking at primarily Swimmer's Cut sized plates, like these that are available in 11"x14" shooter's cut, multiple curvature:

That said, is the XL SAPI form factor (11x14") potentially too large? How does one know without buying plates that might not be right after all?
Interesting! I think some large sheets of cardboard and I will get busy this weekend and I'll mock up from plates and see how they cover in light of that excellent article. Thank you Tucker!