PX12s are probably the heaviest 12 DIN binding out there, so that's really what's weighing your ski down. Griffons and STHs will be much lighter in terms of weight. As far as light skis, Invaders, JO Pros and LTEs are all super light.
BUT, and here's the thing everyone forgets, Ski/Binding weight means nothing when skiing, even when jumping and spinning on rails. It's all about SWING weight, which is basically how fast can the ski swing around. There are tons of things that go into making a ski and binding set-up have lower swing weight (the main one being center mounted with an equal weighted binding - so the toe and heel piece weigh about the same, I know griffons claim this, which is why their toe piece looks so weird), other things like core material, shape, and weight displacement are also factors in swing weight. I mounted my AR6s with PX12s a few years back and while carrying them they were extremely heavy, but while skiing them (jumps, rails, whatever) you couldn't notice because of the skis design.