I’m having serious kitchen envy at the thought of your window seat and two dishwashers.
I completely understand why other posters recommend a sink on the island, but from what you’ve described I don’t think it makes sense for you. You’re not going to be stood there washing up very often if you have two dishwashers.
So either a hob or a clear island makes sense.
What kind of extractor would you use? If it’s above the hob you may have issues with it being in your eyeline/blocking the view. The ones set into the hob take from the space available underneath. The ones that rise up out of the hob need space under as well, but have the benefit of acting as splash back.
What kind of hob are you considering? Induction is easy to keep clean. Personally I love gas, but I would worry that it’s a lot of work to keep immaculate and while that’s not as obvious if it’s against a wall, when it’s front and centre on the island it becomes a key feature.
Would you consider stopping the position of the fridge and pantry to put the fridge at the boundary of the kitchen, and cut down on the flow of people hungry teens into the cooking triangle?