I still use Together 2.6.8[0] for collecting and organizing just about everything. Multiple libraries, built-in previewing, editing, and Spotlight search, no proprietary database (uses Finder under the hood), etc.

There were some changes in version 3 and the subsequent rebranded Keep It[1] which kept me from upgrading, but it might fit your needs.

[0] https://web.archive.org/web/20130315081858/http://reinvented...

[1] https://reinventedsoftware.com/keepit/