I can't find a website for them.
The first pic I posted, the stripy one, also comes in black/white stripes.
And the second one, the starry one, also comes in blue, with black stars.
The third one also comes in red, but thats a girly one xD
If you type Puppy Zzang harnesses into eBay, they'll come up
They aren't expensive either, about £12-13 each.