A container is provided with a frame including one or more support structures each having a stacking post with a thin cross-sectional shape. Multiple support structures having such stacking posts can be provided along the length of the container to enable the container to be used in a stacked configuration. The container can provide an expanded interior loadable width for increased loading flexibility and capacity, and can have recessed upper and lower handling fitting joints in order to provide stronger and space-saving connections between a header and an upper handling fitting, between the upper handling fitting and a stacking post, between the stacking post and a lower handling fitting, and/or between the lower handling fitting and a floor component.