There are 2 tools for this job, a phone book and a credit card or check book. The phone book can be the yellow paper or the virtual kind and your local newspaper or talking to your friends and neighbors with similar problems might be a good place find out where to start looking. Be sure that you check potential contractors out with other references and the BBB.
Have you killed ALL the termites and their eggs and removed the trails and pathways they used to get to your house? You need to do this before the framing contractor starts.