I have decided that my next toolbox will be a Lista TSMW750-0721-M. It is 47″ wide, 28.5″ deep and 41″ tall (including the casters). It has 7 drawers, all full-width with a load rating of 440 lbs. each.
I really don’t have a need for a toolbox longer than 47″. 47″ of width is enough to keep various things together, especially when I have a full 24″ of drawer depth.