For blank ones, I was just going to put "UNSC NavSpecWep" like I have on the examples to keep it "in-world" - kinda cosplay lite, if you will - so that works! I'd be happy to put Southern Regiment on it instead, though, if that's what he/you want.
Whatever works. This is really kind of you to do, so I think whatever will be great. Do you know if you would have the option for a Large Tall? I could pay the difference if there was one. Regular Larges are just too short for his torso usually.