I have wide feet. Just, flat out, wide feet. lol I have two pairs of Bodyline brand shoes. Both pairs fit me surprisingly well width-wise. I think this is because they run a bit wide--at least the types I ordered, anyway. Do you have your eye on any in particular? Perhaps I have the same style and can give you a better overview.
I don't know much about the instep. I have flat feet, if that means anything to you. However, my bodyline's are just big in general. Not big like, "oh this is the wrong size," but more like an attempt at trying to be "10 size fits all 10 size feet" lol Hope this helped!