Rouges American Ale, Dead Guy Ale and Chocolate Stout is popping up in alot of good Off Licence this month. The supplier Eurobeers brought in so if an Off Licence doesn't have it you should ask if they can get it because it should be available to them.
As for the celebration stout, it was a limited edition brew made to commemorate their 10th anniversary so unfortunatly you wont see it around again. I think its popularity surpassed itself thought so i'd imagine they'll brew something similar under a different name in the future. Got a few bottles into our place about two weeks back, might be able to get more in... I'll look into it...