I've got a Snap-on "Heavy Duty Road Chest" that I use to carry all my tools in (dimensions are 31" wide, 20" deep, and 21" tall). This maybe isn't quite what your looking for, but I sure love mine. Because its Snap-on, you know the quality is outstanding, keeps everything dry and well organized, but the darn thing is awfully spendy. Mine sits right behind the cab in the front part of the box, driver's side, and faces the tailgate. I then made a nice large step that mounts to the front spring shackle of the rear axle and up to a support beam on the box. I'm sure you can buy a seperate step, or even running boards that go all the way to the rear wheel, to make access to the bed a little easier, especially if you have a 4x4.