Very nice, what are you going to top the miracle grow organic soil with? Aquasoil?
My initial plan was to use Eco-Complete, but I've learned that Eco-Complete doesn't do a satisfactory job as a cap for dirt because the little rocks are too big. Therefore, I plan to use this product called black diamond which can be purchased at local Tractor Supply stores for a cheap price.
Black Diamond not only looks great, but the grains or substrate are tiny like sand. This will do a much better job acting as a cap for dirt.