I got hit about 4 times when I first built my house in West Alton back in 2006. I used American Lightning Protection out of New Durham. The number I have for them is 603-859-3800. The guy's name was Tom Tremblay. They did a great job, but I'm not sure if they are still in business.
Their brochure mentioned that they belonged to a trade association called United Lightning Protection Association
http://www.ulpa.org/ Perhaps they could tell you if there are any other installers of lightning protection equipment in NH. I checked their website and there is one guy listed in Piermont NH (wherever that is?)
http://www.zerozap.com/index.html