I looked at the link you gave, but it seems they don't sell online, you've got to go into a store?
They've got one here in Harrow, not particularly good (Harrow has most major stores but they're all like rabbit hutches compared with other shopping centres, because the rents are so high). I've been in a huge one in the Galleria outlet centre at Hatfield, bit of a journey for me though. I was looking at Craghopper Kiwi trousers there, half price but they didn't have my size.