Re: Too Late to Buy Deadlands: Reloaded?
Given your mention of Steampunk as being one of the reasons you were interested in the setting, you might check out the "Smith & Robards 1880 Catalog".
You can get a wealth of information on the game setting, adventure ideas, maps, etc from "Trail Guides: Volume I".
Other than that, there's a bunch of smaller adventures and larger plot point campaign books that all provide more information on the world, and some include additional rules and mechanics for use in your game.