Hello Homewood,
Here is a link to a well established modular home builder in Concord;
http://www.epochhomes.com/
I have a good buddy that has a home on the New Hampton/Sanbornton border that was designed and built by Epoch about 10 years ago and he couldn't be more pleased with it! Be aware though that a modular home requires a wide driveway and lot opening for the trucks to be able to maneuver and place your structures.