There is also Metrolina Regional Scholars Academy. My DD attends this school. It is a HG Charter School.
http://www.scholarsacademy.org/educ...fault.php?sectionid=2&url_redirect=1


Something to keep an eye on is the new charter school legislation. There is a chance of some new, charters opening up for the 2012-2013 year. There are several groups that want to open more gifted schools.
http://www.nccharters.org/

I do not to discourage you against Horizons. I think it is a fantastic program. However, it is very hard to get into. It truly is a profoundly gifted program. The good news is that they will take as many kids that qualify. Sometimes it is only 2 or 3 per grade (this is in a district of 130,000 kids).
I hear the school is great about talking to parents, so give them a call.

Good luck in your search and move.