Here's some more info:
It will be approximately 180 feet long and approximately five feet tall. We need a very traditional formally pruned hedge to act as a fence. An evergreen ground cover will be planted on the outer side of the hedge to spill over the small slope which runs in front of the entire length of the hedge. Everything will be regularly pruned. It will have an iron gate at the entrance which opens to a long brick or stone path. The soil for the whole thing is rock-hard solid red clay. I live in a historic 160-year-old Greek Revival/Italianate home. Traditional Boxwood is our first choice if it wasn't such a slow grower. Many thanks in advance!

Still researching...
Any suggestions?
Thanks in advance!

I've been trying to think of plants that I have that would fit the bill, I have red clay, but they don't fit ALL of your criteria. However, I did find this website
http://gardening.about.com/od/treesshrubs/tp/Privacy_Hedge.htm
Hope it helps.

dwarf yaupon hollies. I posted more info for you on my initial post in the Carolina Forum.