Source for thicker c-clips

My car makes this squeaking noise over bumps and while my car was in for inspection yesterday, it went up on a lift and it was pretty clear that the squeaking is due to axle end play (both axles). I've had my axles out already to replace the seals and they looked ok. I figure if I can locate thicker c-clips (or shims) I might be able to get rid of this end play and thus the noise.

Now where do I get thicker c-clips or shims for this application?

I'd really like to get rid of this end play. Am I supposed to gamble on the tolerances of new axles or the lock pin? That sounds like an easy way to waste money. Shims, or thicker C-clips, would do the trick.