No pictures. Ended up creating a pretty nice shelf of egg crate and foam. Coated it with resin and covered it in sand. It looked really nice. The idea was to have that as a foundation and overlay it with LR. Of course, when it came to the tank move - It wasn't as easy as just throwing two big rocks on the platform to keep it down. Man...That foam is super buoyant... I wasn't really expecting that. Spent a few hours trying to get it to stay down but decided it was safer not to use it. Any slight movement of the rock work and I'd basically have a buoy shooting up to the top of my tank with enough force to break my light. It looked good, though. Pretty disappointing. Ok, very disappointing. I expected it to float a little but this was enough to keep someone alive at sea for days. Oh well. An expensive experimental project that didn't work out so well. Ended up using a plexi/pvc platform I had laying around. Not as cool as the other one but in the middle of a tank move...Worked out just fine.
Bottom line - Handi-Foam + z-poxy + sand works and looks good. I was surprised at how good it looked. Forgot who tried it on here before, but it is definitely a doable and interesting idea. If doing it again, I'd only use it in conjunction with dry rock/marco/etc. in the tank itself so there's no worries of it floating.