I would suggest using a Winegard HD-7696P or an AntennaCraft HBU-44 VHF-high-band plus UHF outdoor antenna mounted on your roof, mounted as high as is practical, aimed at 85 degrees by your compass. You may want to consider using a preamplifier like a Winegard HDP-269 if you want to run multiple TV sets from the antenna. You should see all of the Mobile-Pensacola stations without any problem if you use this combination.
Here is a good antenna installation guide to get you started:
http://manuals.solidsignal.com/AntInstallGuide.pdf