The second thing to consider about design, although in relation only with mounted tool boxes, is where do you want to install your tool storage or mounting styles. There are 5 popular options to consider:
• Side truck tool boxes
– installed in bed, on bed side rails, but they don’t touch the bed floor. This is most common type of truck tool box
• Chest toolboxes
– are installed behind the cab, between left and right bed wall, and they touch truck bed floor
• Top mount boxes
- are placed on top of the bed side rails, thus don’t take space in the truck bed
• Wheel well boxes
– as the name suggests these are installed in bed and go over the wheel wells. There are passenger and driver side wheel well toolboxes
• Crossover boxes
– similar to chest type but they don’t touch the bed floor.
As you can see many options take some bed space. However, guys from DECKED invented fantastic truck bed storage system which allows to have a giant toolbox and still have the ability to load tools, bike or ATV above toolbox. See this system in action
Another issue can be visibility, choose tool box that is not going to limit rear visibility. Low profile designs allow seeing through the rear window without problems.