Hello boaz,
Thanks for following up with us.
Based on what you’re describing, it sounds like this will need some custom development. One thing you could do would be to target all the events pages using the “tribe_is_event_query” conditional within your theme’s “functions.php”. Then, if the page is an event page, you can remove the default header image and then pull in the image of your choosing directly.
I’m sorry I wasn’t able to give you a direct response however I hope this was able to point you in the right direction.
Thanks!