Here are a couple of places that might be worth contacting...
cv axle express...located in SLC Utah. They rebuild CVs...send them your old ones they rebuild and send back...lifetime warranty.
cv unlimited...located in Hemingway, SC. Don't say if they have a warranty. They remanufacture CV's and show the VX on their chart.
Think I may be contacting CV Express soon.

As I said earlier...the OEM shafts are the best available. If possible, it is a good idea to stick with them.