I’d say the most imortant thing is to make sure that your boots fit extremely well and that you are comfortable covering big miles in them. Things that wouldnt bother you on a short tour could make your trip unbearable when covering distance day after day. So make sure to thoroughly test these with at least a couple of challenging multiday trips. Even if you have to buy some boots, try them and sell them on craigslist, the extra cost would be well worth it. I’ve used the dynafit pdg’s for the last few years and they’ve been great for cross country travel and capable enough on the descent, but will be looking to sell them after nearly messing up both achilles from an awkward crash. Other boots that come to mind would be the dynafit tlt7, 6 or 5. The atomic backland carbons have an incredible walk mode that beats anything I’ve tried. fischer travers carbon and arc procline look good and the la sportiva spitfire is also a great boot.
So anyway, a bunch of options, but thats one area in particular I wouldnt skimp.
Those objective bc’s seem like a good rec too for the reasons that dan mentioned. I’ve had significant problems with wet snow clumping on the vector bc’s in the spring, but if your trip happens before the fishscales get all scarred up, then you might not have the same problems. Bring some form of skin/ski wax either way.
From reputation, Movement skis are hard to beat for ultralight performance. Fischer also has some new light skis that are excellent in the transalp and hanibal. I’ve used the dynafit cho oyu in a 174 with race bindings and pdg’s for the last few years on multiday trips, and I wouldnt hesitate to recommend them. Volkl bmt light skis even better, but a little more fragile.
Race bindings are well worth the weight savings for your feet, but consider installing them with quiver killer inserts and bringing a back up toe and heel. Depending on how remote you are and what the snow pack is like, that could be a big deal. I’ve broken the toe of a race binding doing nothing special.
Also super important are skins. I would absolutely recommend pomoco climb pro glides. They are ultralight, glide noticeably better most skins without losing much climbing ability, are durable and dont clump very much. The gold standard IMO.
I know all the ski stuff is gonna cost a lot, so i dont want to encourage you to spend too much, but I would consider selling your bivy and cuben flat for a decent sized cuben mid thats capable of sealing to the ground. You’ll get way more protection out of that then a bivy and flat tarp on stormy days. on a long trip like that I’d want the option of being fully enclosed, and to have a little more margin for error (or views!) In site selection.
I’d also go with a couple of 1L smart water bottles and the regular sawyer squeeze over the mini with collapsable bottle. I love the size of the squeeze, but the flow rate makes drinking kind of a hastle, they are harder to clean out and clog much easier. The collapsable bottles are also completley unreliable, i’ve easily gone through about 25 of these. The smart water bottles are more durable and easier to fill up. You can also get a tornado tube for backflushing in the field.
Personally I prefer downbooties (western mountaineering flash) with or without liners over sleep socks. I’ve suffered frostbite and my circulation is not great, so i consider these pretty essential for winter trips. A hot nalgene bottle for feet warming could also def be worth its weight.
I would also scrap the packed long johns for some ultralight puffy pants. I have some with 3/4 zips from borah gear that weigh 6.5 oz and make a world of difference comfort wise when stopped or at camp. Easy to put on without taking off boots too.
Anyway, sorry for the epic read, but i hope it helps. Sounds like an amazing trip!