I ride a lot of arabs and I'm partial to the Abetta saddles. They're perfect for short, wide backs as you can get them with a round skirt and they tend to have a wide, low gullet. They're also synthetic so they're easy to care for and are light weight, though in my experience they stand up to a lot of use.
My only complaint about them is that I don't care for the stirrups they come with. Two of my clients have had them and both saddles needed replacement stirrups after less than a year (they're plastic and crack).