179 bro model or as we like to call it the 'ho' model. iggy gave a nice summary on shape. If it's a powder ski, go straight, less sidecut. My person preference is for the unconventional shapes that are out now. Two seasons on Spats has opened my eyes. Obviously a powder specific ski isn't right for everyone, so having a more traditional ski that still rocks in the soft stuff is a great idea. And you don't need a monster tip, waist is the most important measurement on a powder ski. If you get a fat tipped ski, it will float great in pure stuff, but when it gets skied out you'll be bouncing all over the place. A relatively narrow tipped ski on the other hand with blast through chopped snow, allowing you to dictate where you want to go.
I don't know if iggy mentioned it, but the reason sidecut is no fun in powder is because of hooking. Ski fast in powder with sidecut and make a powerful turn, often you'll feel the outside ski trying to 'hook' up. Less sidecut = less hooking, meaning more controlled powder skiing at speed.
Good luck searching, check out the bro models.
Oh, and to the 1mm doesn't make a difference guy, compare the 182 foils to the 185 guns. 125/87/115 (sorry I'm guessing on the tail dimensions) and 124/90/115. You're telling me that those are two very different skis? Please not that the powder ski is straighter, and the all mountain ski actually has a wider tip.