At the most cut the strips into big blocks with a picture in the middle of each. I applique all the time in a random fashion (using a applique, not-so-wide stitch)and I think the way you have it now, or turning blocks so every other one is at right angles to the ones touching it on a side and putting the pictures in the middle is a great way to go. But the stripes uninterrupted are good, also. I just happen to like a lot of movement in my quilts. Your boy will love it either way, because it is a great boy quilt and it will be HIS!