Nice explanation, Peryn! Touched all the bases, with enough flair to fake the obfuscation!
Prince... Does your father-in-law have a bias against US workmanship? There are several remanufacturers doing a very good job on those drive axles. If he is, however, covering the costs, get the OEM shafts.
Have you heard of the Magnuson-Moss Warranty Act? Maybe you should show him this:
http://www.granatellimotorsports.com/magnusonmoss.htm