I agree that you do not need sashing. But I would swap the top right corner with the second row second from right. That way you would not have 2 dark brown edges together. Depending on size (and what you have left), I would opt for 2 borders. The first would be the same size as the strips and the second could be the same or larger. My personal preference is usually a medium for the first border and a dark for the outside so they both give a good frame. Love the mix of prints.