From someone who was recently (and still is) looking for employment in public school systems in the Raleigh area, here are the web sites you will want to research:
Johnston County:
Johnston County SD - District Home
Wake County:
Wake County Public School System
The trememdous growth you are hoping to avoid is also the key driver behind the massive hiring process by school districts in this area.
Wake County has seen huge growth spurts in its communities and schools (averaging 6,000 additional students each year!) and some areas may have reached their maximum density of development. What you see in these built-out areas now may still match what you see in the 10-year future. The school district is spending nearly $1 Million per day (!) expanding their schools to accomodate these students. They have a multi-faceted plan consisting of: construction of new schools; major renovations of existing schools to increase space; conversion of existing vacant commercial and industrial buildings into schools; and the least popular item - assignment of many school buildings to a Year Round (identified by YR) academic schedule.
Building capacity can be instantly increased by 33% when the building houses students 12 months of the year rather than the traditional 9 months. Students typically attend school 9 weeks on and 3 weeks off, teachers in these buildings are on a 10/2 schedule I believe. YR schools are immensely unpopular with some residents and very polarizing. Subdivisions will sprout For Sale signs overnight like dandelions in the Spring when the neighborhood school goes YR.
Johnston County is not yet seeing this growth spurt. I believe the only thing stopping it is the general housing market malaise caused by the mortgage industry meltdown. Things will PROBABLY change very rapidly in Johnston County very soon, and they will be faced with the same growth problem Wake County has seen and responded to. A subdivision with a "country feel" now, may become grid-locked suburbia within a few months. The roads I have traversed through Johnston County have almost all been two lane country roads. Rapid population growth will not be pleasant for commuting.
Raleigh and Wake County is a melting pot of people and cultures from across the country (and world). Johnston County is currently a buffer zone between Raleigh and the "old south", with portions very accomodating to new residents of any origin, and other portions hating all those "damn yankees".
Renting a home and becoming a substitue (or short term) teacher may be valid ways of determining what area and employer suits you best.