In reply to Frank Boase:
if you are taking a tent, get one with internal structure e.g. a geodesic one. The campsites are often very rocky (like a pebble beach) so not easy to get tent pegs into. We had and AR tent, which had to be guyed out to give it its 'shape'; more than once we had to guy to large rocks or cairns, and as it was quiet ended up using the refuges.
You really can go light; all you need to cook (gas burners, some pans) are provided by the refuges for both those staying in huts and paying to camp. So with use of refuges (+maybe a very minimalist emergency bivvy set-up), i'd be looking to do it with a sub 30l pack.