Tony, we've already got the lightweight thing figured out. Being in our sixties that is essential ! lol
We did a six day hike in nz in march up the dart river and over the cascade saddle with a pack weight of around 11 kg.
We found the heel lifters on the msr lightning ascents to be fantastic. Made climbing steep slopes relatively easy. I'm looking into Altai Hok skis. They describe them as a transition between a ski and a snowshoe...or Skishoe ...or ..sliding shoe.
I've enclosed the link here. http://www.altaiskis.com/blog/products/the-hok/
They have had very good reviews including backpackinglight.com. I can send you links if interested.
I'm thinking of using these in combination with the lightning ascents......snowshoes for steep climbs, and Hoks for downhill. The Hoks are very short and wide with permanent skins and universal bindings, so we can just use our normal boots. They are cheap as well, around $26o us, including universal binding. I'd be interested in your opinion on them.