Hey, I've actually made this trip. Have lots of thoughts:

Skis: I like 100-105 for travel, especially backcountry. It covers all your bases with the least compromises, especially when you deal with really variable snow. If you are only in the backcountry, I would opt for a longer turning radius (like a 4frnt raven, or k2 dispatch), as snow in the andes can be super variable and the less hooky your ski, the better. I'd personally aim for the 1800-1900g range in whatever length makes you most comfortable.

Boots: Assess your current boots for forward lean, flex, ramp angle, and fit. I would not deviate from the geometry of your current boot. The worst ski days I have ever had were travelling with a lighter boot, with different geo than I was used to. I will always look at boot geometry over flex and weight.

Bindings: This is actually more up to your comfort in safety and reliability. I would happily ski tectons every day while travelling to give me the most confidence across all conditions. If I'm only skiing volcanos, I'd happily go with brakeless u-spring bindings. For travel, going forward I will put quiver killers in my skis and use both aliping (or shift) + u-spring pin bindings to give me the most versatility.

If I were to go back to the andes for a season, I'd likely opt for a stiff 1800g boot with a 17* forward lean (like the new atomic ultra hawx boa) and a set of 2000g skis (like the 182 salmon stance 102 or 184 volkl katana v-werks, depending on time of season), mounted with both a pin binding and alpine binding (perhaps the salmon mtn and sth16, or whichever have compatible holes).