The Linex is just a pet idea of mine. There was a thread on safety and best tank location. My suggestion was to look into coating the tank(s) with Linex. Not sure how much weight. Look on Utube for the Linex videos and you will see that everything from an egg to a watermelon to a concrete block survived impact when coated with Linex. Apparently the Gvmt is using it to coat walls to resist bomb blasts. If a tank can't rupture, it gives some addl peace of mind. This probably isn't of any interest to you, but have you considered long travel suspension like the storch and super stol use. Ugly but effective.