OAT (Overseas Adventure Travel, oattravel.com) limits their land-based tours to 16 participants. Their "Morocco’s Imperial Cities Revealed" tour includes the cities you are interested in, and it's 10 days. (They call it 11, but unlike most other tour companies, they count the day you leave the US, even though they assume you don't arrive and actually start the tour until the next day.)
Never been to Morocco, but I did an OAT tour to Sicily, Naples, and the Amalfi Coast, and it was great. Friends have been on several of their tours (including Vietnam and Croatia, not just the usual destinations) and enjoyed them all. Their prices are surprisingly low.