That is adorable. I think I would stitch in the ditch....simple, easy and stitches won't show quite as much. That may not be important to you or maybe you make beautiful even stitches, but new quilters tend to stitch unevenly so in the ditch is a way to help hide the mistakes while you improve. If you find that your stitches are beautiful, then challenge yourself to stitch anywhere and anything for a design. You could even stitch words...repeating the words on his shirts or just writing "love words" for your baby. Love the top and the bottom! They are really pretty and what a keepsake for later on.