Awning or Casement window is the best choice for Kitchen window.
Production limitation for casement window is 37" in width.
Production Limitation for awning window is 45" in width.
Therefore, window with size 37" in width or large cannot be made as casement as it exceeds hardware maximum span requirements. Awning window can be a good option in this case, It does not have middle post and has much better thermal resistance then slider.