wow, but am i missing something? are the hyraulic cylinders actually holding the weight? that is impossible ( i think). they can hold a big thing in place, but only one direction. you can make them extend, but you cannot prevent them from further extending, you can only prevent from pushing together. and the hydraulics are very strong holding - but only in one direction if you put side pressure on them they break. so you need some kind of hinge you move with at least 2 hydo cylinders - one flexing one extending - and the hinge has to do the static, hydro only holds it in place ...
just a thought