We are about the same size, your are a little heavier, but similar.
Your probably going to want something fairly stiff, or at least I would. Also, unless your planning on skiing mainly powder, your not going to want to go too wide, as your going to want the edge to edge quickness, and edge hold.
Until this season I have skied the Volkl G4 in a 188. Its a lot of ski for most people, and can be a bit big in tight spots, but once you learn the ski, its managable. The G4 in a 178 skis like a totally differnt ski, seems quicker edge to edge even. However lacks a little at high speed in my opinion. What can I say, I like a long ski. There are some really good reviews of it in the "Ski Gear Discussion" area. Might want to take a look through. Other skis might be the Rossignol XXX, Fisher BigStyx 84, Dynastar Little Big Fat, and many others. These skis might be a little bit bigger than what your looking for, as they tend to need a lot of technique and leg stregth. Wider skis are not as quick edge to edge, and can magnify bad technique, but handle steep powder well.
I agree that the Rossignol XX might be the ski you want. Although fairly soft, its my understanding that its a good all around ski, and holds its own anywhere on the mountain. Somewhere in a 177 or 184 might be a good length. Might want to give it another look. Similar skis, would be the Volkl G3 (mentioned above), Dynastar Intutive 74, Stokli Stormrider or maybe the Fisher BigStyx 75. Check out other midfat all-mountain skis, and I believe that they may have what your looking for.
My new steep hardpack ski is the Dynastar SkiCross 66. Its stiff, and very quick edge to edge. I like it a lot at high speeds, and suprisingly, handles powder well. I've never had it very deep, but a foot or so and its fine. It jumps through the bumps, but there is little room for error. It goats just fine, although the weight is a bit high. Might want to look at other brand's skier cross skis such as the Salomon Crossmax and the Atomic versions. SkierCross skis make good all around skis in my opinion.
Length will be a question for you. I have a few pairs of skis in my quiver, and they are all within 10-15mm in length of each other. Length of the ski is important in swing weight, but when I'm in the steeps, I try not to jump turn if I don't have to. I still try to carve as much as possible, even if its more of a controlled skid. This is where edge to edge quickness comes into play. So keep an eye on that as well. Get out on a few pairs and demo. Even if your not taking them into the steeps, pay attention to how quick they are edge to edge on the groomers, how well they hold that edge, and put them into the air a few times. Whey billy goating steep terrain, you will find yourself in the air a lot. A ski that you can quickly change directions with at the last moment is very important.
Good luck with the new skis!