PDF U Append Batch software automates the process of appending multiple PDF files. It will append your many PDF documents into one PDF document at the click of one button, and also has command line options for further automation so that any append can be automated from other platforms. Other features include drag and drop, append page ranges, saving batch lists for later use & many other options.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.