Allow clients to print statements from the client portal

I would like to be able to send large batch billing statements using the theranest message service rather than sending the batch statements to my clients' personal emails. This would be more secure. Right now I don't feel comfortable sending large batch statements over email and have been using theranest messaging to send each statement one-by-one. I would like to be able to send everyone their statements at the end of every month using the more secure theranest messaging.

my clients would like to be able to run and download superbills at anytime, whether they have been paid in full or not.

more specifically, previous superbiills