Securing confidential info via web hosting company?

Hi all,

I have a client who currently has a pseudo-website. It’s essentially WordPress blog where he uploads pics and short details of each image. Since he already uses WordPress I was thinking about simply integrating my design that I created for him into blog sites. But he also has confidential and important documents that he wants to have access to via online either through an “intranet” or another secure/password protected method that only he (and a couple of other team members) would have access to. Any suggestions as to how my client would be able to do this?

I assume he would need to register with a well-known web hosting company in order to have his files accessible and hosted? Or what are some other methods he can do to store, upload and download confidential files from his website (and anywhere else). And can all this be done/compatible with using WordPress or Drupal? Don’t know if this is the appropriate place to pose this question but any direction/instructions would be very beneficial especially since it would eventually be my responsibility to help the client achieve this.

Thanks so much for any help!