The majority of A1 Merchandise is now available from your local dealer to order, but the supply is very limited until July, reasons being that AG loved the stuff so much that their dealers bought most of it up, and also that the Audi UK board believes the items are "to Young" for their expected target audience so haven't as yet authorised AUK to stock many of the items.
this may well change if demand is higher than they expect,
the merchandise lists are available from your dealer in hard copy (very limited) or via download, I don't believe the items are on the Audi UK web shop as yet.
Oh, and hard copy brochures are available from dealers now as well, (but you probably know this already).
They should also have A1 configurators in the showrooms by now also.