Clipless MTB Shoes for wider feet
To start, Keen makes a commuter bike sandal that is clipless, so you may look into that if you like the fit of Keens.  I know that Specialized makes wide sizes in their shoes as does Lake.  There may be others out there, but that is what I am immediately familiar with.

As far what to avoid, most of the European companies (especially the Italian companies like Sidi) tend toward a fit that is aimed at a narrower foot.  Sidi, makes a Mega option that is supposed to be wide (I believe), but I haven't ever seen a pair to try and the regular Sidis fit me horribly (I also have a wide foot).