Since there are a few Arkham City skins, I decided to get images, links, and some other details together so that you could find out where to get the ones you wanted. I’m sure we all have a preference one way or another and it’s unknown if it’ll be possible to get all of the bonus skins on one game.
Firstly, is the classic Batman uniform used in the incredibly cheesy and campy (but hilarious) series where Adam West portrayed the Dark Knight, showing the old blue and grey colors with a contrasting yellow and black Batman logo. If you are in the UK, you can get this one by preordering the game at ShopTo.net, or Toys R Us if you’re in the US.
After that is the Batman Beyond skin, taken from the animated TV series where Bruce Wayne has retired from his life as a vigilante, and the mantle has been taken up by Terry McGinnis. The Batman Beyond suit is worn by Bruce, and is all black with a red batman logo in the chest. This can be acquired by pre-ordering the game through Gamestop.co.uk.
The third bonus skin is from The Dark Knight Returns, which has Batman in a black hooded cape and grey clothing, utility belt, and tights. This one comes with the standalone game, and is not specific to any retailer.
There you have it, three skins for Batman from different periods in his position in the media. If more of them come out I’ll likely amend this. Hope you enjoy it.