I have picked up some of the outfits. When you buy an “outfit”, you get the plans for it. You can then construct the outfit for yourself. You can not trade it.
However, every character you create will have access to anything you buy in the Atom Store.
Keep in mind that everything is cosmetic. Nothing is a “game item”.
When you see something that looks like a game item… it is just a skin to make a game item look different.