Yes I think I would put a hanging sleeve at the top and another sleeve at the bottom to help the quilt hang straight. Have you thought how you will quilt it? Are you going to try to do it on a regular sewing machine or long arm? Personally I would go for a long arm. If you don't do it yourself, I would select someone who has a lot of experience in machine quilting and know how to work with heavy tops. You will need a lot of support for the top, I am guessing a strong batting and backing, and lots of quilting.
Quite an enterprise, you have made. I would really research how to quilt it and hang it before you do it so you know it will hold up to hanging, and possibly lots of handling. You have honored our heritage as well as the men and women who served.