Elaborate on big mountain ski. Sometimes the best powder skis don't double as great big mountain skis, but it depends on what sort of "big mountain" skiing you're doing. Generally a true big mountain ski is going to run a little narrower and a little stiffer than your average luxury pow ski. There is definitely some overlap but in general I see them as two seperate categories of ski.
Big Mountain Skis:
Salomon Rocker 2 115
ON3P Billy Goat
Moment Bibby, etc.
K2 Pettitor or Hellbent
Salomon Rocker 2 122, etc.
I hear that Armada JJs can lay down a nice carving turn. Have not ridden them though. My advice would be to head over to TGR and ask the folks there. You'll get more in-depth advice if you so desire. If not, NS is great.
If your going to buy a chargerish ski from armada, look into the Norwalk, not the jj. The jj's a great ski, but its sidecut isnt designed to be a charger. Also look into salomon rocker2 115 or atomic automatic. These skis all have more rocker in the tips than tails (no tail rocker in the norwalk) so they're definately more directional, but the litttle bit of tail rocker allows you to smear your turns and make them more playful, if you so choose