Pat,
I'm pretty sure you'll find that support will work better for you than width. A Morton's neuroma is generally caused by a collapse of the transverse arch, ie the arch that runs ACROSS the foot, under the ball of the foot. As this arch collapses it compresses the nerve which runs between the bones that form this arch.
As Greg says a metatarsal dome will reform this arch, but I find that a normal fitting shoe for your foot shape helps to buttress the ends of this arch. It's also common for the longitudinal arch to collapse at the same time, so a pair of orthotic inserts may be appropriate. There are a number of studies published which assert that off the shelf orthotics are just as beneficial as custom made. The trick will be to find one that places the met dome AND the long arch correctly.
You may be better to find arch supports and add your own met domes. I generally do this by taping the dome correctly positioned under the foot, and then standing on the arch support and marking it. Even better if you can do this in the shoe, but you need to use a few tricks to mark it.
The other thing to think is acute and long term. Initially you need to settle the inflammation. The met domes will assist this, but you also need to use a soft sole any time you aren't using them eg around the house. I find Crocs are pretty good for this.
Rod