tripp-bishop - we have made one such customization where in we are pulling in the data from another platform and indexing it in SOLR index, and using the Lithium endpoints, we are making an HTTP request to the SOLR index, and further, we have called this endpoint in a Custom Component and this Component is placed on the Search page.
We have implemented the Facets as well, and the search relavency is completely in our hands with index being in our control. So we show the community data below the knowledge base data because that is more relavant to us.
Let me know if you need more information on this.