Sky don't have an N Router as yet, no. One is in testing to be released in the next few months apparently.
Sky 'say' you can't use one, but I was advised if you can, and they won't help you with settings, usernames etc then they won't stop you, they just won't support you.
Sky are also changing to MER/IPoE which uses MAC addresses to authenticate on their servers so I'm not sure how much longer you'll get away with a non sky Router.
I don't think I've ever had a router that hasn't supported MAC address cloning.
there are programs available that will extract the user name and password for you...