I like Henderson because they offer some more flexible suits (easier to get on) like thermoprene and hyperflex (IIRC). Other brands offer similar strechty wetsuit but I don't know what they are a called. Everyone has a different tolerance for temperature...but I would think a 7 mm or a 7/5 mm suit would be appropriate for NC diving.
A "flexible temperature" range might be hard to find. A 7 mm would be too hot if you wanted to go the the caribbean occasionally. A 3 mm suit would be more appropriate for tropical diving, but I just don't think it would keep you warm enough in NC...especially if you are going to go to any kind of depth to do wreck diving (which I think NC has a lot of).
Wetsuit is def the place to start in my opinion (I'm assuming you already have mask, fins, snorkel, and boots).
Let me know if you have any questions about what to buy as a newbie, because I'm in a similar boat and have done a lot of research/asked a lot of questions about the best order in which to buy the equipment. Obviously, its very subjective but I think I have a pretty good idea what the consensus is.