If you're really likely to spend a fair bit of time belaying, I'd probably look at a synthetic instead, unless you can be sure your outer layer will keep the down 100% dry in spindrift.
However, I think your top two choices will both do the job well. Just to add another in, PHD stuff is top notch, and the Minimus might just do the job brilliantly. I don't have one, but my PHD sleeping bag is superb for the weight. You might miss a hood, unless you pay the extra £35 on top of the already top end £299 price! The best costs though.
http://www.phdesigns.co.uk/minimus-down-jacketI use an Alpkit Filo down jacket for longer breaks on the hill, and camping all year round. I find it very good for the money, thought being stitched through in the main, its not quite as warm as my previous Rab Summit which was heavier but lasted nigh on 20 years.
If I'm ever sat around camp in winter and start to feel just a bit cold, I find that putting a down hood up makes me warm very quickly, and I normally have to drop it back down again 10 minutes later. The other thing that seems to make a big difference is a "Buff" round the neck, whatever else I'm wearing.
Make sure whatever you buy is long enough not to ride up at the back when sitting about.
