You are likely to have good results with any of the
Ipomoea nil
http://davesgarden.com/guides/pf/adv_search.php?searcher%5Bcommon%5D=&searcher%5Bfamily%5D=&searcher%5Bgenus%5D=Ipomoea&searcher%5Bspecies%5D=nil&searcher%5Bcultivar%5D=&searcher%5Bhybridizer%5D=&searcher%5Bgrex%5D=&search_prefs%5Bblank_cultivar%5D=&search_prefs%5Bsort_by%5D=cultivar&images_prefs=with&Search=Search

Ipomoea purpurea
http://davesgarden.com/guides/pf/adv_search.php?searcher%5Bcommon%5D=&searcher%5Bfamily%5D=&searcher%5Bgenus%5D=Ipomoea&searcher%5Bspecies%5D=purpurea&searcher%5Bcultivar%5D=&searcher%5Bhybridizer%5D=&searcher%5Bgrex%5D=&search_prefs%5Bblank_cultivar%5D=&search_prefs%5Bsort_by%5D=cultivar&images_prefs=with&Search=Search

Ipomoea tricolor
http://davesgarden.com/guides/pf/adv_search.php?searcher%5Bcommon%5D=&searcher%5Bfamily%5D=&searcher%5Bgenus%5D=Ipomoea&searcher%5Bspecies%5D=tricolor&searcher%5Bcultivar%5D=&searcher%5Bhybridizer%5D=&searcher%5Bgrex%5D=&search_prefs%5Bblank_cultivar%5D=&search_prefs%5Bsort_by%5D=cultivar&images_prefs=with&Search=Search

Ipomoea alba
http://davesgarden.com/guides/pf/adv_search.php?searcher%5Bcommon%5D=&searcher%5Bfamily%5D=&searcher%5Bgenus%5D=Ipomoea&searcher%5Bspecies%5D=alba&searcher%5Bcultivar%5D=&searcher%5Bhybridizer%5D=&searcher%5Bgrex%5D=&search_prefs%5Bblank_cultivar%5D=&search_prefs%5Bsort_by%5D=cultivar&images_prefs=with&Search=Search
Ipomoea turbinata
http://davesgarden.com/guides/pf/go/69456/
or
Ipomoea macrorhizza
http://davesgarden.com/guides/pf/showimage/65128/
would all be suitable for the moonvines...

The MG's do well with a Phosphorus based Bloom Booster...despite Myth-conceptions regarding various MG's and 'fertilizers'...

Plant 6 to 12 inches apart...

All aspects of MG's answered in the multiple threads located in the Forum dedicated to Morning Glories...

Hope that helps...

Ron

Here is a link that might be useful: Dedicated Morning Glory Forum

wow, Ron really has great answers: I just bought a couple packages and sprinkled them on the ground, they did wonderful! Then each year I collect the seed pods and sprinkle them in new places. They are really pretty twining up through my fruit trees. I even sprinkled them in my honeysuckle for added color. My only special recommendation is that if you have full sun, put a layer of potting soil (a huge giant bag of miracle grow is only $8.) then they have protection, slow release fertilizer, and moisture retention. With southern exposure it sounds like they will have full sun all day, you will have to keep them watered faithfully.

Regarding morning glories in North Carolina, I have had great success in both full sun and part-shade. One year I grew them in containers (regular potting soil, probably) and they made it easily 15 feet up a dead tree. The next year they were along the back of a raised bed (part-shade) and they also grew prolifically (compost, topsoil mix, no fertilizer). The biggest problem I've had is that they are prolific re-seeders. So the next year, I had tons of volunteer plants and anticipate having tons again this year. They are pretty though and seem to be very easy to grow. I have direct-seeded them with success and also started them inside and planted them as soon as they sprout and get their first leaves. One suggestion - if you want to have a mix of colors, I would sprout them indoors and then plant them in the arrangement you want. Last year, I got way more purple than blue when I direct seeded.

As for moon flowers, I have also had success growing them with morning glories. I think it looks really beautiful. The only suggestion I would have is to nick and soak the seeds, sprout them indoors and plant them either right after they sprout or let them get a little growth first. I have had a hard time direct seeding them for some reason. Good luck!