To the PCB airport, I'd definitely do 231/87/81/20/79/388. It's only about six miles, if that, from where 81 ends in Bruce to pick up 79 in Ebro, and that's only because you have to cross the Choctawhatchee River. True, no four-lane after you leave 231, but it's pretty clear the rest of the way.
Again, though, do watch the flashing lights, especially the one in Holmes County at 185 (2?) and 81. And I do not like to travel 81 at night, or especially in the wee hours of the morning. In daylight it's a very good route.
Sounds like the plan for me! Thanks for all the valuable info! We will be extra careful. Really looking forward to being there.