I think that layout would be crazy awesome if you were going the high-tech route with a field of flowing UG.
Since you're going low light with mosses and such? You still have all kinds of options if you decide to use the stones you've got. Their scale is perfect for the tank's dimensions. A few small twigs of manzanita covered in moss and bam, you have an instantly perfect scape.
Whoops, forgot to add: Hope you're considering putting a black background on the tank. That will make it easier to hide sponge intake covers and your ZooMed outflow. Also disguises the black silicone and draws your eyes to the center of the tank or more directly to your desired focal point.