Can I do this with Drupal... Easily?

I'm a bit confused on how to word this myself, so I'll give my scenario and hopefully this will give you an idea of what I'm trying to accomplish... and maybe some feedback on possible solutions I can use.

I'm reviewing a property management site for a company that has 75 properties. Each property has one or more investors, who will log in monthly to download a PDF report for the property. The property management company, wants to be able to manage things in a central location and in bulk. Here are an example of the updates they want to perform from a management screen

1. Add a user to multiple properties.

2. Add a PDF report to each property, from one screen.

Using Drupal, I've built a custom content type called "Property" and used CCK to customize the fields to store the basic information I need for each Property. I enabled "File Attachments" on the content type to store files, but this does not allow me to provide a file description. I now have a working Property page that looks pretty good, except the file descriptions... but I'm clueless on where to go next!

I'm not sure if doing things in bulk, adding a file to all of the Property content types from a single screen is possible. I'm not super worried about assigning the users to multiple Property from a single screen, but I should choose the correct setup to support this in the future. Finally, I think a year or two down the road they'll want a way to archive/hide attachments 1+ year old, so I would like some type of management screen to update all the attachments for all the properties from the management screen.

What are your thoughts... Where should I start reading? Also, for somebody skilled in Drupal could you throw a rough time estimate in setting something like this up... I would like to weigh the consultant versus the "struggle along for weeks" value proposition in getting this setup as well!

Thank you!