In reply to mik:
Scarpa and Kayland are wide.
La Sportiva are narrower but the widest part of their boots tend to be further forward than on Scarpa.
Salomon are narrow in the toe box.
Some brands do extra wide fitting in some boots BUT the extra volume that accrues often results in problems.
Most boots are about a D fitting
Scarpa are an E.
a lot depends on where the boot is wode and where your foot is widest. If you have a narrow foot but broad forefoot/toes, Sportiva or Kayland might be a better bet than some Scarpa.
if your foot is hobbit-like (very uncommon) ie fat and chunky all over with good bulk above the arch then the Scarpa extra wide fitting (SL only I think) might be a good choice.