Hello Blitzo,
Hounder uses Lucene as an index, but that is pretty modularized, so
you could probably change that to use an xml file. The complex part of
that schema is already in place in Hounder, namely the distribution of
queries, the gathering and merging of responses, the cache and rate
limiters, etc.
So yes, I think Hounder is a good platform for implementing this idea.
Let me know if you need specific help with this.
-- Jorge