I'm 7 years older than my (now) husband, and we were approved for a K1.
Every country is different, OP: Check the regional forums and see what those who've been through the process for the Moroccan embassy have to say - every consulate is different.
If you pursue the K1, make sure the USC is at the interview. The consulate may or may not allow the USC in the interview room, but their presence will be known and it will make a huge impact.
I look significantly younger than I am, so despite me being older, I look younger than he does. That may have played a hand in our approval.
Read about the possible troubles you two will have at the Embassy on the MENA regional forum....your case seems to be one of them. K-1s are frowned upon, especially when the USC is female and a lot older than the beneficiary.
Getting married there and then applying for a CR-1 seems to have more success.
