Link categories in separate pages

I would like to add a medium-size link directory to my wordpress installation — approx 1000 links in 20 categories.

It would look like this:

1. A starting page named ‘Links’ which would contain only a sorted list of categories (category name and category description), each pointing to a child page in which the links themselves would be listed.
2. Ideally a hierarchical directory structure similar to the Open Directory Project, in which child pages may contain links to sub-directories.
3. The whole thing (category names and descriptions, link titles and descriptions) should be searchable — integrated into general site search.
4. Link descriptions should have longer maximum length — seems to be 150 characters max now, but we would prefer up to 512 characters.

Has this been done already?