Using diffrent size wood planks for fleetside bed?

[brawley]

Im about ready for my wood bed but was thinking of using wider wood planks and spacing them evenly, for some reason they vary in widths from the factory, I thought about starting the metal strips along the edge of the wheel tubs so everything is even. But I dont know if there is a reason not too ? or if it will workout -so before I try I wondered if has anyone has pictures of wood beds that are diffrent sizes or odd ways of doing this ??thanks