Looking for a way to SEND Echosign agreements from code.

I have echosign installed and it's working well. I also build the agreement from code and it works well. Now, I would like to actually do the SEND from code.  

So far - all of the examples I have seen - have been for creating a custom SEND button - utilizing the AgreemenTemplateProcess VF page, and specifiying the MasterID.  But - in this case - I've already built the agreement, and custom PDF attachment.

Any thoughts?

Thanks

We currently use complex Conga merge documents, and then attach them to an Echosign agreeemt.  Well, now I'd like to find a way to drop the Conga documents from the process.  Document is getting even more complex, and I'm going to use visualforce and apex to create the document that is to be signed. So, ...

Can visualforce rendered as a PDF, have embedded signature tags?  

Thanks