I lived in Charlotte for a few years and know just southwest of Charlotte is a good fish store by the name of Fintastic. I haven't lived down there since '09, but I imagine they would still be in business, as they were by far the best in the area. I'm also not sure how far that is from Wilmington, but it's worth the trip if they have what you'd be looking for at the time. They had healthy and good quality fish at reasonable prices, and a helpful staff. Check them out if it's not too far for you.
They are still in business, here's their website so you can get an idea of what they have/carry-
http://www.fintastic.us/