First, thanks for your answer.
Unfortunately i get an Error when using them both together:
The object "Flowpack\ElasticSearch\ContentRepositoryAdaptor\ElasticSearchClient" which was specified as a property in the object configuration of object "Flowpack\SearchPlugin\Controller\SuggestController" (automatically registered class) does not exist.
Same problem here: Using SearchPlugin with SimpleSearch
How to get started without the SearchPlugin?