Thank you everyone. A special thank you to Annaquilts, toverly and cjsews for your ideas and suggestions. I now have a plan that fits with my style and how to attach the onesies. I will suggest my perception of a quilt using your ideas to the person who requested the quilt. If's she likes it, I will do it.
Toverly, I have a pattern with the clothesline! I never even thought of this. It will easily adapt to using onesies.