If I want to add cc: to the letter to several individuals and not all at the same company, do I include the person's name and company name in the cc?
Yes. If the copies you list are going to people at different companies, you would indicate such (along with their titles). Group those at the same company together.
cc: John Smith
Richard Roe, President, Acme Industries
Joseph Sixpack, Controller, Amalgamated Bucket