[deusu]

I don't know sphinx at all, and my knowledge of lucene is very limited. Which means I don't know how they would compare to DeuSu.

[karussell]

You should really have a look into both. I'm curious: Why did you create a new software from scratch if you do not know existing?

If you'd base a project on lucene/solr/elasticsearch or sphinx you'd also increase the chance of contributing to it.