I need a web site to share and manage files online, similar to box.net and sendspace.com but much more simple.

These are some of the required features:
- Nice web design
- Ability to co-brand the site
- Ability to select one or multiple files for uploads/downloads
- Download/upload one file at the time
- Download/upload progress bar
- Ability to enter a short description of the file

Types of accounts required:
- Master account: to manage and administer the site
- Regular accounts: these are clients that will own a space to manage and share files for a group of users.
- Users: are the users under a regular account that share and manage the same files.

Master account will be able to:
- manage the site
- create regular accounts and users
- assign access and privileges
- limit the number of users that a regular account can create
- limit the space of regular accounts

Regular accounts will be able to:
- create users to access and share the same files
- create folders and subfolders
- assign access privileges to their users to access specific folders

Users can:
- Upload/download one or multiple files (one at the time - no parallel download/upload required for now)
- Remove files

More features might be added in the future as a second phase.