Lots of advice kind of all over the map here.
My wife and I skied the Chugach last March at Alaskan Rendezvous Heli Guides
. The skiing was spectacular, some of it was waist-deep, some of it was breakable crust, some of it was wind-buffed. The skiing was incredibly good and some of it was quite deep.
My wife took her regular Jackson Hole powder skis, the K2 Axis AK, and never felt even the slightest need for anything else. The AK is 118-88-110.
If you plan to ski 3,000 vertical foot, 50-degree faces in ten turns at 60mph, then you'll want a huge, wide ski. If you fall more in the "human" ranks, a ski in the low 180's with a waist of around 90mm will serve you just fine.
Find out which operation you'll be skiing and get them on the phone. They'll be able to tell you what you'll need and whether they have loaner or demo skis that would work for you.
Unless you have money to burn, I wouldn't suggest BUYING a pair of skis just for what you'll find in Alaska.
But by all means...
have a fantastic time up there. I'm jealous.
In case you never saw it, here's a link to one of the reports I posted:http://forums.epicski.com/showthread...=alaska+report