Catalogue/database/organizational app?

I am an environmental designer (fancy-speak for architecture and related fields) looking to create a database of media - best practices, inspirational photos, links PDFs, text files, video, snippets and so on. 

I am searching for an app to help me do this.

Ideal Criteria:

OS X Must include tagging I would like to add captions/notes to accompany media files Searchable Linkable (internally) Exportable Easy capture/input of media

Any and all help is appreciated.

Cheers,

Freeman