Women's average width = B. Men's average width = D. So, buy your size in men's and you're getting a women's wide. The Sidi Mega is a MEN's wide (E or EE, I can't recall).

Remember that when you go to a men's (or the mega) the whole shoe gets wider, not just the forefoot. It's common for women with a wide forefoot to NOT have a wide heel, but to be rather more triangular. You may find that if you go to a men's you need to do something to prevent heel slippage.

Susan