Griffin & Wong is a design house that specializes in silk, hand painted wallpaper design. They are based out of Vancouver, BC. The current collection consists of 22 Chinoiserie and 5 Western Scenic designs which can be hand painted on a variety of coloured silk wallpaper backgrounds. Papering an entire room in one of their designs would be costly, but you can get the look for much less with one or two panels. Like this.
The panels are approximately 3 feet wide and can range in height from 4-12 feet high. You can read more about the ordering process and cost here.
Some other designs.
If you're looking for some large scale "art", these panels could do nicely. Our stairwell is crying out for some blossoms and birds to keep it company. Sign me up!