I lived in Myrtle Beach when I got certified back in 1999.
I did my certification dives on the Bill Perry and City of Richmond wrecks. I have dove about a dozen times and about 60% of the time the vis. was lousy to ok.
To really get to a good site you have to go way offshore and those are long expensive charters.
But, it is worth the trip if you can handle being on the boat for 10-11 hours. and can afford $100 or more a person for a 2 tank dive.
Charter wise I do prefer Express Water Sports over Coastal Scuba. The few times I’ve been out with Coastal it was a full boat and they went out in pretty rough seas that were questionable on safety in my opinion.
Now, keep in mind that no matter who you go out with your probably going to have a full boat of divers because with the slow economy none of them can afford to go out with anything less than a full boat.
Honestly, I would recommend a live-a-board like Blackbeard or a trip to the keys. I have done both and if you look a the cost per dive day you can’t beat it.