Found these, made by Spohn Performance. Some of you know they sell the adjustable panhard bar as well. According to Tony, the suspension Guru on the SS owners site, these adjustable arms will work with up to 2.5" of rear lift. I believe he runs discounted pricing through his site, but these still aren't a bad price for what they are.
http://www.spohn.net/shop/2002-2009-TrailBlazer-Envoy-SSR/suspension/