Im 98% sure this is the correct part:
They are, though at a little over $8 a pop before shipping and then having to do the work to replace them getting a used, or even a new, controller would be a much better option, but that is the correct part # at Mouser for anyone that's looking for them.
@ SweetIvy - If you opt for replacing the sticks check around in the Buy / Sell / Trade sections of some gaming forums, you'll get a lot better deal on a pair pulled from a controller that are still in excellent or like new shape for far less than what new ones would cost you, as well as the stick caps (the part you see and touch) to go with them, as the actual controller is the only place to get those, unless you go for some 3rd party type ones on eBay or the like, though I personally don't recommend them.