Looks like that space could make a lovely dining area, perhaps work on keeping the brick and the large timber beam and perhaps Lime washing them to give a lighter look, that would make for interest in that area with your new white kitchen. Are you planning to do anything with the ceiling. have you finished it yet, would love to see it.

With limited measurements provided, ie: return wall next to the sliding doors and the width of the window it's hard to give the correct result. Given that there's only 540 between the window and the return wall , that suggests that there's also only 540 to the other corner? I had approx 1000 between the island, sink and cooktop with the island running across the space, I was going to suggest that the island is flexible and can be rotated with stools facing the window. I agree that the "U" shaped kitchen is restricting, one way in and out especially with kids. I don't think the sink is a problem under the window and being able to see the kids as the return wall is approx 900-1000 deep, this measurement not shown on plan. can you confirm the measurement is 450 into the other corner, this would also restrict any tall units going into that corner cheers

I would do sink on back wall in front of window. Stove on the side wall that has the window. Could do 2 windows either side of stove. With stove on side you can still chat whilst cooking. Tall storage on opposite wall and fridge

If you want to continue with the wood look maybe something like a parquetry, this way it's a pattern defining the area but still blending with the floorboards