A very dedicated individual to this hobby has been able to reproduce the original Aurora Big Ryder pup trailers.  The originals are very rare and expensive if located.  These trailers are shorter than the standard 40' reefer that you normally find.  They come with a removable container that can be interchanged with train accessories as well.  The 3rd wheel can also be used to pull larger trailers if desired.  Only 100 of each container are being produced (unless noted) so these will become a collector item in the future.