Janne Savolainen makes nice boxes, I have one and have been very satisfied with it. Sturdy and empty weight is reasonable.
Mine is black but next one will be some other colour, it becomes a bit too hot in the field. In Finland ok, but there seems to be warmer climates
Just bought me a 4m Xplorer2, I need to have another box (longer...).
Here is the link to Janne's firm, he is a professional box maker: