I'm more interested in a setup that's light for the approach and retains decent skiabilty for the descent, but nothing extreme. I was thinking of Dynafit bindings because of the weight savings, however, seeing the weight of the Dynafit compatible boots I was thinking it might be better to go with Naxos or Fritschis and use my climbing boots (Scarpa Omegas).
You must be looking at the wrong Dynafit-compatible boots? Also, climbing boots are incompatible with Naxos or Fritschis.
You need to go either one of the following two routes:
1. Dynafit Classic/Speed bindings with a lightweight rando race boot. The new Scarpa F1 shaves some ounces off the standard F1, and for next season the rear lever won't flop around as much, making it even better suited for climbing with crampons. Or, Dynafit is revamping its boot line for next year, but the current Race Pro boot would be a good choice, or for more weight but more support for skiing get the 2-buckle Lite or 3-buckle Evo. The old discontinued MLT4 or various versions of the old TLT4 S/Pro would also be good.
2. To retain your climbing boots, you need a Silvretta 505 binding, or the old 400 or 404.
For skis, get a rando race ski or an all-around lightweight ski with waist in the low 70s. (Or the Trab Duo Sint Aero that somehow keeps the weight at rando race level but has a 73mm waist.)
As for setups designed around a Scarpa Matrix, Spirit 3/4, or Garmont MegaRide, those are nice lightweight skiing-oriented setups (and I love my Matrix + Dynafit Comfort bindings + Trab Duo FreeRando skis), but those are not oriented toward climbing. For lightweight ski mountaineering I have the Dynafit Evo 3-buckle boot + Dynafit Comfort binding + Trab Duo Sint Aero ski, and for when the emphasis is almost entirely on the up, I have the old Dynafit MTL4 boot + Dynafit Classic/Speed binding and Atomix TM:11 ski (although I sure wish it was the Trab Duo Race instead).
