HealthSouth used to be the big dog at BHM, they had their own air force which included two GV's and was run by a general officer. But they've fallen on hard times - I think they're down to a light jet and a turbo-prop. I think Drummond and McWane are the only Gulfstream operators on the field. Amsouth has a couple of G200's. There are a bunch of Lear operators there - SunTrust, Harbert, and O'Neal Steel, a few Citation operators and some outfits with KingAirs and smaller, but I don't think there is anyone there to replace HealthSouth.
Good luck,
GV