We are planning on using elasticsearch, too. It's basically the best. Maybe just need to charge some sats for the service, rather than refusing to offer the service. @jimbocoin was also working on something in this direction, if I recall.
Yeah, elastic search is really good for full text searching (ive used it in the past for high volume logging/log searching). It probably is the best for this, enterprise grade. I have seen a few things here and there that might be better but they were so new and I forget their names.. Managing an elastic search cluster is basically a full time job on its own 😎