I am a former Marine, and I do work for the Air Force, but on the East Coast of Central FL in Cocoa Beach. The first thing I would suggest is that you get a killer resume, and then be very proactive in looking on USAJOBS for announcements, but when you go there and type in Air Traffic Control Jobs and hit enter, look over to the right, and select the option that says you decide which announcement you are eligible for. If you don't you might miss out on a job opening because it is a trick that managers are using to limit the number of applicants so that they can have a better shot of picking someone up they already have in mind.
I won't lie to you, you have to start now and keep at it. Understand that if you want to go DoD you may have to go wherever hires you and work your way back, or if you are set on the Destin area you might have to go contract and work your way into DoD in that area by making some connections.
Up in that area there is Hurlbert and Eglin and Tyndal.