Awww, my favorite subject quilt! A big rig! 20 years behind the wheel of one of them babies,& now I've hung up the keys, but I keep making quilts for them! The bunk mattresses are 40"X80" in size. The size of dorm room bunks in college, that's why they have trouble getting sheets for them. Now to your dilemma, why not find out what he likes in sports or such? Personally, red & black are 2 of my favorite colors to play with, so coming up with ideas is easy for me. Chevron? Rail Fence? Carpenter Star (Gray would be my 3rd color), just about any beginners pattern. I make them come out to about 60"X80-82". Looking forward to seeing it finished.