Hi Alex,
I, too, would recommend the Montbrook site in the winter months. It involves collecting for the U. of Florida, but it is well run, welcoming to all levels of amateur and professional paleontologists, and prolific in fossils of all types. Large complete turtles are common. When I was there my favorite find was a juvenile gomphothere tusk. The Florida Museum of Natural History in Gainesville, FL is a must, if you go to Montbroook to fossil hunt.
In NC traveling to the far eastern point of the Aurora Fossil Museum in Aurora, NC offers collecting that you can keep from their “pit of pungo” by sifting the gravel reject material. That fossiliferous material is mine reject donated to the museum by the phosphate mine in Aurora. Occasionally large mako teeth (1-2 inches) and megs ( up to 2 inches) can be found, but more commonly the teeth are smaller (<1 inch). The museum also offers great displays of shark, whale, and other miocene-pliocene marine fossil material.
Mine access for collecting purposes in both North and South Carolina is either non-existent or extremely difficult to access, due to liability issues. In the low country area of South Carolina I collect by diving the rivers, but you must have a Hobby Divers License and December is not exactly ideal for scuba diving. LOL. Now summer- that’s a different story! If you go to Charleston, SC, I would highly recommend the Mace Brown Museum.
Hope this helps