Thanks! Took quite a few revisions to get to this point but we are both pretty happy with the way it turned out.
Thanks! Still haven't secured any of the rocks together but it is all remarkably sturdy. A few of those smaller rocks sitting on top are loose but the main foundation and everything is really solid. So now I am wondering if some of these rocks even need to zip tied or secured together. Maybe just the smaller and loose rocks need zipties and I can epoxy the bigger rocks into place. I went to HD and picked up some (4 sticks :lol

JB water weld epoxy. It will be used to epoxy rocks together and also to cover up zipties to keep them out of sight.
One thing I found key to making the aquascape work was using the flat cut rocks for the foundation. Flat cuts are rocks that are cut in half so one side is perfectly flat, great for placing on a flat surface. I think we had 6 flat cuts, those played the biggest role in keeping everything stable IMO. Also have a hammer and chisel ready to shape any rocks flat for better stack ability or shaping if needed. The hammer and chisel were used on our rock more than once to make everything "work" and fit together nicely. The other big thing is to have fun with it, don't force it to go together. Sit and play with it for awhile, stack and re stack to see what is pleasing to your eyes.
Oh one more thing, once you have it how you like it, take 100 photos so you can put it back together in your tank. Even take photos as you dis assemble it. That way its semi easy to figure out exactly what rock goes where.