Check out Fly Guys Hollow Reef thread:
http://www.thereeftank.com/forums/f6...ef-111814.html
He used the acrylic
rock lift system. You can cut the 3/4 inch rods to any length you want and will not have to worry about them flexing or breaking. That way you could have the rock be higher, but still not have it just resting on top of other rock. As you move away from the overflow you just use shorter lifts.
There are also other methods and threads out here where people have used PVC pipe or eggcrate structures and zip tied the live rock to those structures.
Another method is drilling the rock and using driveway marker rods to connect the pieces of rock together through the drilled holes.
You should be able to search for any of those methods on here and see which one will best suit your needs.
I like the sound of your idea and am looking forward to seeing how you make it work.