For a beginner quilter, I am going to suggest that you buy patriotic fabrics and cut them in a single size squares, 8 or 10 inches each. Then arrange them in an appealing way and sew them together. It's not the fancy quilt you were thinking of, but it's a lot easier and much more likely to get done. Later you can make the more elegant version, but the guy getting this might not want it. My friend who doesn't sew has made 3 of these quilts, although not in patriotic fabric, they are still very pretty. For the backing you can choose your favorite of the patriotic fabrics or make full size slabs across the back that you sew together of several of the fabrics and I know your friend will love it.
This is an example of what I am talking about.
https://thecuriousquilter.wordpress....part-1-topper/
There are military panels out there. If you buy one of those, you could use it as a center and measure and fit the squares around it. Or buy several and place them as you want.
https://www.ebay.com/sch/i.html?_nkw...+fabric+panels
Edited to add: I thought of this fun pattern "Boxtrot" This would work, if you buy some of the Navy panels and then sized your strips to be the size of the 17x17 Navy panels. This will be a quick, relatively easy pattern.
https://www.bing.com/images/search?q...tern&FORM=IGRE