Piet, buddy, I'm from California so it's kinda anything goes here. But . . . if you want to look more adult & professional, short is the way to go.
I've had long hair most of my adult life because when I was acting I was doing a whole lot of Shakespeare & directors always wanted my hair long. It's short now - really short, actually - & a lot easier to deal with.
I found that I attract different kinds of girls with my hair short as opposed to long.
All 3 looks work really well for you so my question to you, bro, would be: What's your favorite? What makes you feel most like yourself & lends you confidence? Whichever look that is right now . . . go with that look!