Replying to Mixed DIN Advice

I've been asking different shops and taking surveys to determine what I should set my DINs at, and I've gotten answers everywhere from a 5.5 to an 8.5. Please help!
I'm a 14 year old free skier who skis park competitively, but loves to hit the pow and cliffs a lot as well. For my all mountain powder setup, im running a set of Armada Invictus 95s with Rossignol FKS. I'm getting up to 150 lbs, I'm 5'7" or so, and I'm a very agressive skier when it comes to ungroomed terrain. I need to be able to drop >25' cliffs with these, and on my last pair (DINs were 5.5) my heel would sometimes release on landings of bigger cliffs.