Well... I am going to order an atomic ELE 18" not sure on the amp yet, but I need help designing a box. This will be the first box that I have ever built. I would like to have a lot of spl while maintaining some sq.... I drive a 99 ranger ext cab. Heres the dimensions that I have to work with height 20 inches, width 19 inches, depth 40 inches. any input is appreciated.