Sidi makes several shoes in wide widths (denoted with the "Mega" tag, e.g. Genius 5 Mega, Dominator 5 Mega). Unfortunately these are generally in the $200 range though you can sometimes find them on sale. I have both of the above shoes, in 48 Mega. They are quite roomy...they almost feel too loose but once they break in they sort of mold to your foot and don't move around a lot, even though they never really feel tight.
Also, I think Shimano makes a variant of one of its road shoes in a wide version...I think it's the R151W or something like that.