Welcome to the board to mtg and KellyB! I grew up in Richmond but didn't do much diving while I was there. I would recommend The Dive Shop (on Broad St. I think). I'm not a regular customer of thiers, but evertime I do go in there, they are always super helpful.
I lived in the OBX for the past 8 years and did tons of diving there. I now live in Florida and I can tell you it is 2 completely different sports. Bad viz here is the best viz there. Cold here is the warmest I ever was in NC.
Outer Banks Dive Center in Nags Head has great trips out to the wrecks. I've seen viz from 3' to 100'. Count on the bottom temps being around 70-75 late summer. There are even some great civil war wreck beach dives you can do. Diving is not like the "ooohhh, aaahhhh, pretty colors" stuff here in FL. It is more about the history and exploration of the wrecks.
The OBX is only about 3 hours from where you are. Make a weekend out of it. If you're a YMCA member, you can drop the kids off at the daycare in Nags Head, go accross the by-pass and do a beach dive. Not a bad deal!