A Chest Might be Best
Cross boxes are popular. But if your truck has a tonneau cover or you're considering adding one, a chest box is the only style that'll fit under the cover. And since a chest box sits at or near the height of the bed rail, it doesn't obscure your vision through the cab's rear window. This style box bolts to the bed floor, so you won't be able to slide sheet goods or lumber under it. On the plus side, a chest box generally holds more tools than a cross box.