Looking for a digital notepad

Hi, I am looking for a digital notepad/paper to be used

  • during audit: I shall allow upload of documents, filling them directly and then, be transferred back.
  • for reading and annotating document, regulation.

Do you have one or used one you could recommend?

I found the Sony DPT-RP1/B 13” Digital Paper, other proposition? E Ink MeeNote?