The Wallpaperwebstore are excellent to deal with. I've ordered 4 times from them now and every time I received the wallpaper in about a week, shipped to New Zealand. Contacting them by email or phone was also responsive and pleasant.
Strengths
Large collection of wallpaper.
Affordable prices.
Fast shipping.
Improvements or suggestions
Description of how tax is deducted/applied for overseas customers could be clearer.