I have a complicated document containing files with a letter as the first document followed by several article type documents. I have done this by setting up a master tex file with all the frontpeice information, defining common style elements and whatnot, then adding the documents with \include statements. Is there a way to use the letter document class for the first file then switch to the article class for the rest of the files?
This FAQ answer discusses some solutions to this type of problem. The only one that I think is likely to work for you in this case, is the
pdfpages based solution.