I tried searching for suitable wholesalers, there were a number of sellers but most had relatively limited stocks.
I suggest visiting their official site and see if you can purchase directly from them instead - Link hidden: Login to view
They have stores all over the UK, you can use their store locator to find the nearest one to you.
We have one supplier here in SaleHoo - Link hidden: Login to view
They're based in the US.
Hope this helps :)