Here's a link to Cingular's website where you can check coverage in a certain location, even down to a street address. Maybe that will help a bit?
http://onlinecare.cingular.com/support/maps.do
I got that link from wirelessadvisor.com. If you post there, you may have luck from people who are in that area. I have found the people there friendlier and more helpful than some on howardforums.com. It is a smaller community.
fuzz