Henderson Beach State Park in Destin might be an option. I don't know if they have sewer hook-ups though. It is actually in Destin right on the main drag, and about 5 miles from Topsail campground. We didn't stay here, but drove through while staying in Topsail. Each site has a secluded feel because of the trees and bushes. Looked well maintained and had large beach area. Sites were gravel I think. Also, I haven't stayed there, but there is an Alabama state park in either Gulf Shores or Orange Beach that has been completely remodeled over the past 2-3 years. It is across the road from the state resort.