These shutters were made to fit from a custom window covering company.
Not sure if you could find them in standard sizes or pre-finished.
I would check your local mill work and window covering companies.
They are beautiful and well worth the effort. Good luck!

I wish there was such a thing as standard when it comes to window sizes. I am finding that my windows are gigantic, which is why I bought this home, compared to what is considered standard. Do you have what they call Big Box Stores in your area? (Home Depot, Lowes). Those stores have websites that show prefinished plantation shutters that you can order on line or inside the store. They come in painted white, natural, dark stained, etc. And they sell them in several widths and lengths. Plantation shutters can be ordered from so many places on line: Blindschalet, Steveswindowsandblinds, blinds.com are a few. They make them custom and ship out pretty quickly. I am finding I cannot decide where to purchase mine. So many options!

Seems like you have a wonderful home with gigantic windows!! It can get costly for shutters, though...
If you have solar protection in your windows for sun damage and privacy with trees and landscaping in some areas from the exterior, maybe you don't need to cover some of your windows at all...
Yes, we have Home Depot and Lowes in our area, but I have not used them for shutters. I did not recognize Blindschalet and Steve's windows and blinds, but I would get several estimates and compare.