IMO you will get the best effect if your underlying SW architecture is CQRS/ES, as it maps nicely to it.

For the initial discovery/ideation I would use Big Picture EventStorming as it's a much simpler notation understandble to non-technical people (if you know what is a sticky note - you can participate;)

IMO EventModeling is more comparable to Software Design EventStorming but with Project Management, full documentation, SDLC, etc.