Have you considered using Adobe Acrobat as a means of gathering electronic signatures?
I came from a paper based company as well, but recently have started a position where all document reviews are performed on PDF's generated from the original source documents, (usually Word documents but not always). When sent for a shared review, comments and edits to the documents are made on the PDF document, and are visible to all other reviewers. After the review cycle is completed, the source document can be updated and sent out again as a PDF for approval with a digital signature. The signature can be certified since it is password protected, and can only be generated by the person who set it up.
Search Adobe Acrobat 11 Pro for more information.
Good luck!!