If you are looking for custom fabric or wallpaper
I use Spoonflower for buying cute fabric, and the neat thing, is they will make fabric with any design that you create, too. Now they do the same thing with wallpaper. Pretty cool. So if you can't find the wallpaper you have been dreaming of, you can design something and have it made.
Just thought I would share!
Here is a link that might be useful: Spoonflower