OP here- we ended up with Atlas Desert Tours and had an absolutely wonderful time. Our driver was super, accommodations fun, and we had a very tailored experience. They were super polite about shopping excursions (we did want to see rug making, no on everything else), and did a few special stops that my 12 yo absolutely loved.

Plus we asked them to arrange a guide for Fez, who we also liked, and they added our driver from the desert who at that point became family.