Thank you all for your comments and thoughts. This is a wonderful, encouraging community.
I ended up going with the 1" red border and then 5" navy border.
I am really undecided as to how to quilt this. I think I will free motion quilt circles in the border, so that I have some organic movement in the otherwise really structured quilt. I don't know what to do in the body of the quilt. I can't see myself stitching in the ditch on every single seam, but I don't want anything to take away from the quilt as it is. Any other ideas?