This is gonna be difficult because of the competitor rule, but there's an online store that sells them for £95 and is currently offering £10 off if you pay via Google... plus free shipping - although I think that this might only be if you spend £89, so you'd need to add something else like the accessory kit.
As for accessories, you ought to get a protective case for it, and definitely get some of those protective films that you cover the screen with so that you won'tdamage it with the stylus. Get one of the kits (my son has a Big Ben kit) as it works out cheaper and you'll get a spare stylus and a wrist strap too.