I'm not too familiar with Kibi so I can't confidently speak to whether it would help in this case or not. I'm hoping someone else on these forums will chime in.
As for how long indexing large SQL datasets into Elasticsearch would take, its difficult to provide a generic answer. I would recommend trying this out for a subset of your dataset to get an estimate. I can say, however, that indexing data from relational databases into Elasticsearch is quite common. In fact, there is even a Logstash input plugin that will read data from a relational database with just a few lines of configuration: https://www.elastic.co/blog/logstash-jdbc-input-plugin. Then you can combine that with the Logstash output plugin for Elasticsearch to send the data to Elasticsearch: https://www.elastic.co/guide/en/logstash/current/plugins-outputs-elasticsearch.html