Now see, it's like I always say: If you're not real careful, you'll learn something new on this forum every day.
If you are grabbing hubs from a 'pick-a-part' you only need to worry about the clip rings if they are Warn hubs (Aisin and Superwinch re-use your existing clips). If the clips aren't available, don't let that stop you from getting the hubs since the clips are only a buck or two at any hardware store.