In reply to Mike Hewitt:
As you say, what fits your foot shape is a major factor. I would recommend a heavier weight B2 or a lightweight B3. I used the Sportiva Trango Extreme Evos for several years and found them excellent. Review here:
http://www.ukclimbing.com/gear/review.php?id=1782
I run warm so for me they were fine for 4,000 metre peaks and brilliant for rock / mixed / snow / ice. Some people find them narrow. They are, imo, borderline B2 / B3 - more towards B2.
More recently I have used Sportiva Nepal evo. A little stiffer, a little warmer, a more technical boot that fits me beautifully. Imo a lightweight B3. Info here:
http://www.ukclimbing.com/gear/news.php?id=4157.
I suggest trying on lots of different boots and see how they fit.