Another option is to use Conga Composer to generate the document with signature tags in it and then send for signature with Conga Sign.
To upload the document and add tags
Click Preview and Tag.
Tag the document with signature fields, initial fields, or any other fields you require. Drag and Drop the blocks from the left-hand panel into the document.
Documents requiring more than one signer have an extra bar at the top of the document with color-coded names to distinguish field blocks. You can manually add signature tags as well. For a list of signature tags, see List of Conga Sign Signature Tags.