Never did Annapurna but did Mustang (right around the corner, so to speak) with a DSLR (Canon 50D long since retired), an EF-S15-85, lots of batteries and my 70-200 F/4 IS. Wore the camera on my chest in a TT Holster. Were I to do it again, I'd try to go with even less weight.
DON'T underestimate the effects of altitude on your health! Great region and great photos.