I may have just not found the right shops yet but I'm wondering why I can't by high quality weapons and armor from the normal shops but I can buy magical weapons and armor in the Cold Fired Armory in House Kundarak (according to ddowiki).
Masterwork is supposed to be very well made
Sliver, mithral, adamantine, and other metals are a variety of alternative metals to Iron.
While certainly expensive compared to normal iron weapons and armor, I would expect the material choices no harder to come by than +1 weapons and armor.
The same should go for some of the exotic materials used for clothing.
Just a thought.