Re-reading your initial question, display and search would be two different idea's
Elasticsearch would have no problem holding the data and making it searchable. Getting it in there can be done with Logstash, or even just simple CLI commands (or any language you like) Parsed or unparsed.
While we could make this work but the end result would most likely be something custom.
Now thinking outside the box,
You may want to look at a Wiki, maybe like Confluence, Mediawiki or really any wiki with search capability (some do plugin into elasticsearch ) . There you would make each "Invoce" a different wiki page (or multiples on the same page for the same person) and when you search for something it would give you your page options. Seems like what your actually looking for.
Heck, you could just upload them to a private GITHUB or Bitbucket repo, that would give you everything with very little work. Search, file storage and display of the data in a raw format. It would not be as pretty as a wiki but would be secure and web gui for people to use.
IDK hope this helps.