If you add an extra rack on the bottom you could still have your water pan in it's normal place, a pan (foiled) to catch dripings, AND a lower rack to cook on. The extra rack would only have to be 1 1/2 - 2" above the current rack. You could still get butts on the bottom.
I still like water more than sand. Cleanup is not that bad. Foil the outside, spray some pam on the inside about 1/2 - 1 hr before you fill with water. Stuff comes out pretty easy.