Has anyone here converted their single rear wheel 2500 or 3500 to a dual rear wheel setup?

Aside from swapping out rear axles, I have found the following to options. Any opinions/advice would be great! :ro)

JcWhitney (http://www.jcwhitney.com/webapp/wcs/stores/servlet/ProductDisplay?productId=5779&catalogId=10101&storeId=10101&langId=-1&TID=2023881)

Southwest Wheel (http://www.southwestwheel.com/chevyconversion.htm)

There is a mechanic around here that has done it to two of his 2500 Suburbans. Used them to pull his race trailers and crew. He added the standard factory style wheel well extensions/flairs to cover the extra tire and was good to go. I know he sold one of the 'burbs and it's still working with no problems.