re: Know of any suppressor dealers in south MS?

I believe that is correct. The transfer from FFL to FFL has to be between licensees that also pay the Special Occupational Tax (SOT). Not every FFL is an SOT. On the other hand, not every SOT openly handles NFA items in their main business. You might be surprised at what your local gun guy is equipped to handle but might not put out front and center. Ask them and you may get an answer you like.

At the very least, they'll know who to point you toward, if they aren't an SOT. The NFA community is fairly small, so the guys who are involved tend to be known and know of each other within the larger gun community. My guys at the range, my trust attorney, and my NFA guy all know each other personally.