I went to Dauphin Island last year in October and TORE IT up. I would have to imagine the fishing would be good in July. If you want to fish from the surf go to the "west end" beach. I was using a (2) 12' Mojo Surf with a Daiwa Saltist B30 - 20lb test main line and 50lb shock leader. I was using 8/0 circle hooks and throwing pieces of cut bait. We had a house on the bay side and caught live bait at night off of our dock. If you can get fresh mullet for bait that seemed to work best.
I threw one rod long and one rod short. I caught multiple drum off the beach and load of saltwater catfish. I actually got spooled by something, I am assuming it was a large sting ray. It almost pulled my rod out of the rod holder and with the drag slammed down I couldn't stop it.
I also took a small charter boat to Grand Bay and caught massive drum and jacks. Let me know if you want the captains information, he was really good.