In reply to GridNorth:
> Yes smaller pack. I would say 35 litre absolute maximum if you want a pack that is useful for other situations even smaller if you are buying specifically for this trip.
Totally agree with the above. As much as I'd love to sell the more expensive bigger packs, my advice is to go as light and compact as possible in the Alps. The bigger packs are actually appealing and look cool. I love Grivel's flagship Alpine 45. But they serve "bigger" purposes than climbing 4000's in the Alps IMO. Nothing wrong with buying one...
I use an old (18+ years) BD 35L rucksack. These things last ages. Or at least should last ages. Make sure you get what you really want and need. Within reason, don't bother too much about cost. It will pay for itself.