i'd tell you to get two skis. a fatty rocker ski for pow and a skinnier ski for all mtn. but if you only want one ski you might check out the chronic blends, line elizabeths, or something along those lines.
I ski mine all mountain and they rock the shit out of everything. Granted they do more amazing in the powder than the piste but they still kill it everywhere!
Instead of getting one ski for front side and one for the pow, just get the Rossi S3 and have one ski that does both. camber AND rocker = murder the whole mountain.