Here is a link to the faculty qualifications for SACS schools: http://www.uta.edu/irp/assets/SACSFacultyQualifications.htm
One thing I have been wondering is whether SACS requires that the degrees/credits be regionally accredited. I have seen faculty job listings at SACS-COC accredited schools which specifically state that NA degrees are sufficient, but it seems to be unusual. Most such schools specifically want RA credentials only.
Since we are a SACS-COC accredited school, these are the guidelines that we use. Faculty must have degrees accredited by an agency recognized by the U.S. Dept. of Ed. and/or CHEA. This would include NA degrees, although you are correct that the preference is definitely for RA degrees.