I really like the first pic. Being a scientist (therefore having a science brain!), I think your son will like the clean format of the first one. The only change I would make would be to move the lowest white patch over a bit towards the middle. This would appear more balanced and it would provide a great spot for you to put a small label.
Your T-Shirt quilt is wonderful (balanced color and pix) and that is was your first quilt is amazing!