Visual drag and drop editor for placing fields on a PDF document in a browser

Visual editor for placing dynamic fields on a PDF document inside a browser. Use PDFJS to render a pdf, then allow user to select and drag text, numeric, drop-downs, signature and other (expandable) fields onto the PDF. Allow user to drag to reposition and use cursor keys to nudge for pixel perfect placement. Allow user to define a KEY and default value for field, along with the ability to change font-size, line height, width and other CSS properties. Application should feel like [login to view URL] but much, MUCH less complex. Allow user to save fields (POST JSON to PHP script which we will write) . App must allow loading of PDF and render fields to PDF previously saved. These are the foundation features and I can provide complete scope of work. We will write ALL server side code to allow your editor to obtain a list of editable PDFs along with retrieving the server side JSON object defining the fields already placed by the user. Screen shot show work that has already been done by our in-house developers. We just need this done faster and you MUST comment the heck our of you code as we will need to evolve and maintain it. Need to be able to communicate in english for periodic discussions via email or Skype.