Once I become fairly proficient in karate I want to study Aikido. It was actually my first choice and I was signed up through Rec and Parks but they didn't have enough enrollment and had trouble getting an instructor.
Like I said, SMAC has a new center off industrial park drive in Waldorf. It is a good dojo.
You might find your plan very challenging... and you may end up slowing your progress by doing it in that order. See, I studied Shotokan Karate for 6+ years... In the Marines, I took Jiu Jitsu and Judo recreationally (for ground work) and MCMAP as required (which is a mix of several arts). Having begun Aikido last year, I've found it more difficult to grasp the movements, because the movements in Aikido are typically circular going WITH the flow. The footwork is vastly different...
Whereas in Karate, you are facing the threat head on with a block or by slipping past an attack to the inside for a strike.
Anyway, just some food for thought...