I don't think you're going to find any other then the XL axles. Think of it like this, why would they make extended axles for the Savage X when you can just buy the XL axles. Any particular reason why you don't like the XL ones? Now you have the option of getting a set of wheels with a larger off set, that will make the stance of your truck wider.
If you end up using the XL axles you're also going to need drive cups from the XL if I'm remembering that correctly, hopefully somebody else can confirm that one for me.