Check out some modern kitchen ceilings on Houzz and see if there's anything you like: https://www.houzz.com/photos/modern/kitchen/query/ceiling/nqrwt Then hire an architect or designer who can help you with space planning. : ) rf

How will you clean it?

Or clean the windows?

Shoji screen frames might work with strong beams to reduce sagging. Lot of spiders, lot of dusting.

Run a few large beams wall to wall. Drywalled and painted, or stained timbers to suit the rest of your decor. Conceal uplighting on top to highlight the ceiling and provide ambient indirect illumination.

Right now there's just an open space. There is no kitchen. When your appliances are installed along with counters, cabinets and island I can't imagine that there will be any question about where the kitchen is. Those will define the kitchen space.

Don't box the kitchen in. ???