Hello Justin,
Here is one hatch chart I found for north Georgia and southern South Carolina. It looks pretty extensive to me. It lists the actual insect and then in one of the right hand columns it appears to list flies that imitate that specific insect.
http://www.ngatu692.com/Hatch_Chart/All_Year.htm
Edit: I opened this link and IMO the flies the writer recommends to "match" the insects listed are pretty lame. There are a few like the Hares Ear and Prince nymph that are generic attractor flies will work almost everywhere. But many of the dry flies recommended are not at all good representations of the living insect.
I freestone stream (not a scientific definition) is one that typically has very little aquatic vegetation in it and lots of boulders, rocks, and gravel on the bottom. Typically, but not always, freestone streams have flows, and water temperature, that fluctuate wildly based on snow melt, rain, cold weather, hot weather, they get most of there base flows from smaller tributaries and creeks that flow into the larger stream or river.
Tailwaters are named such because at some point up river there is a damn that is holding back water from a large lake or reservoir. Depending on the depth of the lake or reservoir, and if the release is from the bottom or the top of the damn, the flow and water temperatures are controlled much more closely than on a freestone water that is plagued with the variables of cold winters, hot summers, too much snow or rain, not enough snow or rain etc.
The quality of fishing is generally better and more consistent in a tail water than on a freestone. The hatches are much better because the water temperature in the spring, summer, and fall rarely is less than 48 degrees or greater than 60 degrees near the release point from the reservoir. If the reservoir, or lake, is deep the water down near the bottom is going to be very cold and when it is released form the bottom it will keep the river below the entry point cold for many miles downstream. Whereas a freestone river can only depend on the springs and little cold water creeks that enter it to manage the temperature of the water. In the summer that is the reason why many trout streams get low and the water warms up to the low 70's and greater while the water in the tailwater is always getting cold due to the bottom release.
I know there is a correlation of PH levels of alkalinity and acidity regarding freestone rivers, tail waters, and spring creeks (BTW spring creeks are not tailwaters but distinctly different than freestones) but I don't know the data regarding that aspect of my answer. I only know that if I had my choice I would only fish tailwaters, or spring creeks, because the emerging mayfly season, and the resultant better fishing is far better, and much more consistent than on freestones.