Admin File Manager & News

Hi,
Rather new to WP, been using Joomla for a while now. What I am finding hard to get information on is 2 functions I would like to add to WP. I require a File Manager/Vault where I can upload files into folders and assign folders to users or user groups. This is an admin only feature and it will allow me to use my WP admin as a cloud storage facility. If this is not available do I look for Amazon S3 plugins for the hosting of the files and if so can I still impliment the user/user group permissions?

Secondly, as I have alot of admin members I want to be able to leave regular messages in the admin so that they would appear on their dashboard when they logged in. Would also like to have the ability to tick a box to send out the new news item posted in the admin.

Your help is appreciated and thank you in advance.

Edit: Forgot to mention I have WP 3.3.1

Andrew