Hi Andrew,
You'll find lots of help here, and plenty of varied opinions, I am starting to advise folks that when it comes to cars and 'build vs buy', ask a lot of question and try to distill what is best for you from a variety of responses.
You're in Columbia SC?? You have 2 events near to you. There is Sandhills in Jan/Feb over in the Sandhills State Park near Cheraw. There is Cherokee Trails which is in TN just across the NC border on US 64. (Near Cleveland TN). Since the typcial rally distance to tow is 300-500 miles for many competitors, you're in a good location! Neaxt nearest events would be Rally TN about 1.5 hours WSW of Nashville, and STPR in northern PA.
For Rally-X, the sports car folks in the Raleigh area have the most active program near you; check the "Event Announcements" or "Southeast" forums. They have one coming up on Sep 17th , I believe.
We are about 6 hours north of you, in western VA, and you are welcome to hook up with us for anything you like. From your message, it's not clear if you are going to try to run a car or want to co-drive. Can you give us more info?
Regards, and welcome,
Mark B.