In order to see the list of available skins, go to the Fortnite application -> Menu-> Carrer -> Vbucks -> Shop. Then, tell us the item you are looking for, and we will send it to you.
You can even see the list at this link: https://www.fortnite.com/item-shop
Warning: We need to wait at least two days for Fortnite to allow us to send items.