"If I select Records Being Browsed the pdf contains all 'pages' (statements) in a single pdf, using the e-mail address and account number from the first record only; and, if I select the second option, then a single (unformatted) pdf is created for the first record only."
This is the expected behavior for printing/previewing/saving as PDF. You are expecting different behavior and not getting it.
Do you want to send a PDF of "All the records in the found set that belong to client John Smith?"
If so, then you need to set up a found set of just the records belonging to a given client/customer and now "records being browsed" will generate the PDF you want.