How did I miss this thread?
As Glen mentioned, my gray argyle and waistcoat were from the British Shop. They're good quality, well-made (in Scotland ), and a good deal for the price.
The times I've stopped by, their in-store stock of Argyles was limited to gray, brown, and navy blue.
So - good quality product, at a lower price than USA Kilts or the Scottish Tartan Museum, but a limited selection to choose from. I can't speak to shipping, as I've always visited the actual store for purchases.

Oh - and those are UK sizes, so expect them to be slightly smaller than corresponding US sizes.