A fundamental difficulty for all Christian missions who wish to proselyte in Arab countries is that most if not all have laws against anyone proselyting anyone.
Arabic is spoken in most of the countries in North Africa, although French figures largely too, due to French colonization, which is why so many countries speak English.
I am not aware of any Arabic speaking missions in the LDS Church, but the missionary department in SLC could answer that best for you.
Here are some contact details that will help you connect with the Missionary Department, or else the Public Affairs Office, each of which should have the information you are seeking.
50 E. North Temple
Salt Lake City, Utah
Phone number: 1-801-240-2190