Boy oh boy

As a mom of two girls, I don't have nearly enough "boy" fabric in my stash. So I was very excited when a friend asked for my help sewing a baby quilt for her brother's first baby boy. I poured over fabric selections online for hours and drew up concept boards of different fabric combinations. In the end, we decided on these fabrics below, most of which I got from Fabric Worm. Cynthia has an amazing selection plus she's fantastic to work with and has a great sense of style. She patiently helped me by making sure the fabrics I was selecting indeed matched since viewing true color of fabric online can often be so tricky. I highly recommend her shop.

Aren't those guitars fantastic? They'll be the backing. The stripe will be the binding. And the other fabrics (minus one that is still in transit) will be used on the front. The actual design of the quilt is still to be determined. I should make it easy on myself and do a simple patchwork but a modern log cabin or maybe square within a square seems very appealing to me. What design would you use?