Thanks a lot for the responses!
Regarding the jacket:
My decision on Peak XV was heavily guided by the Cold Thistle blog reviews (coldthistle.blogspot.co.uk/2010/02/belay-jacketsthe-heavy-weights.html). I just honestly don't know good alternatives and the reviews/fora/material/etc. available on the Internet are usually heavily US-biased.
Annapurna seems quite a bit colder. John Griffith (
http://www.ukclimbing.com/gear/review.php?id=3994) was quite happy with PHD Hispar on Denali, though he did not summit. I know that XV Peak has been used successfully on Aconcagua and Denali. I have no idea about PHD Hispar, though - admittedly, it is significantly lighter (700g vs 1kg). Another alternative would be Marmot 8000M, but that just seems like overkill.
What would you do? Would you go for PHD Hispar 800 (interestingly, made out of 900 down)? 500GBP seems like a bit of gamble, absent any concrete reviews/comparisons/recommendations... I guess the alternative would be to import Peak XV (paying around 100USD for shipping) and risking totally bad fit/sizing problems.
As regards Pants:
I am afraid that Photon Pants will be too cold. Patagonia does not intend to make DAS Pants available in Europe until March - I have confirmed that the local distributors are not allowed to import it. You would think that checking the size for Patagonia pants and ordering myself would be easy. Interestingly, I have 28'' Rock Craft pants bought in the US and 30'' Alpine Guide pants bought in the UK, both with exactly the same waist size... oh well! I might just guess one way or the other and hope.
As regards the sleeping bag:
That is probably the easiest to order from the US (thought still very expensive) as the size does not matter. Great advice on Marmot Col MemBrain, though! Is there anyone by any chance who has any clue how Wraith and Col MemBrain compare? A quick look on the specifications seems to suggest that Col MemBrain is lighter (1.77kg vs 1.99kg) and has slightly higher fill weight (1.07kg vs 1.02kg) with the same down (800). Has any of you used either?
In general - what would you do in my situation?