Paul - good on you. If you look at the skiers who are technically proficient (PSIA D Team, former US Team Members, coaches, etc) no one is rocking anything over 100 underfoot in powder. That is unless they are receiving a sponsor check.
I don't know where you are in the spectrum but would advise that you take a few day clinic that will drill basics, then look at ski choices. Get wrapped up in efficient movement patters before you get wrapped up in equipment. I don't know if he is teaching, but look up John Egan. He may be able to recommend a path.
John Seifert at University of Montana has been studying the effect of wide skis for years. His findings are that anything over 80 and you start to torque the shit out of your knees. Based on my experience (and assuming that you have been on wide skis for a while) you probably have exceptional rotary movements, but edging and is pressure control needs to be developed. Once you develop those assets you will likely gravitate towards a narrower ski. Part of that will also likley be yoga - and increasing range of motion in your lower core.
BTW... I live out west. We used to live at / teach at Baker and now live in Durango, where I teach at Purgatory. My skis are 73, 78 ad 82 underfoot. 95 for touring and trips to Silverton.
Enjoy!
FAT skis kill my knees. They always have. Not so much in deep snow, but once I get on groomed runs or the firm, I'm crippled after four 3000' vert laps. Having a big quiver of skis to fall back on is great if you have the "means". However, in the modern world of resort skiing, getting back-up skis from the car to the slopeside rack is brutal. (Locking them up is always risky too. Will they still be there when you need to switch em out?)
The "one ski quiver" concept makes sense for the majority of the skiing public. Skis and binders are expensive and if you get that average of 5.2 days per season, then owning a full quiver is cost prohibitive. The Kastle MX 89 is one of my favorite, working well in all but chest deep conditions. And how ovten do we see snow that deep these days?
Back to my personal problems: Much of this knee pain is a result of my stance. I do my best to keep my feet apart, but to no avail. Many a full-rockered ski with camber under foot has helped alleviate the strain, I simply had to stop skiing them from tip-to-tail and get used to skiing the 140cm under foot with less focus on completing the turn and taking things down to a minimal turn shape. It also reduces the tip and tail "flutter" which drives me nutz!!!
There was a time, so long ago.... when a RS/GS ski was perfect for me when skiing powder. Thankfully, FAT skis came on the scene, along with other great inventions like the Internet, smart phones, flush toilets and cable TV. Nonetheless, I do often wonder if I could strap-on a skinny ski and make it work in snow over my boot tops as I once did?
