I got the 41" bottom and top boxes. They are absolutely GREAT! You can get deep drawers for the 41" for almost nothing if you need another deep drawer. The slides are mounted so you can remove 2 shallow drawers and replace them with one deep drawer.
One complaint from full-time mechanics is the wrinkle finish - it catches grease & dirt - harder to keep clean than a smooth finish.
I stepped up from C'man 26" boxes and can't afford Snappys. These boxes are great!