It's so funny b/c I got it into my head to make this same exact coat. I almost did, and I was going to use several of the below patterns for a basis, so I don't have much to add there.
However, the biggest hint I can give you is to go look at this coat on the Neiman Marcus website. you can zoom in to the front and get a much better idea how that center panel is really working.
I actually ended up choosing to make a different coat altogether, so Good Luck! Can't wait to see how it turns out