I have been doing lots of research on superchargers and have been very happy with what the Procharger system has to offer. I know of many people who have them on various vehicles and they are all extremely happy with them. I have been dealing with a shop that has done all the work on my viper and specializes in installing the procharger systems. he has installed them on many corvetes which have the same engine as the hummer. I asked him what would be the best deal he could give to us H2 owners and he is willing to do the stage 1 charger which is 6 to 8 lbs of boost in the polished finish for $6700 complete installed and all programing done. If anyone is interested I can give you his shop #.Here is the link for Procharger
http://www.procharger.com/TRUCK_SUV/truck_suv.shtml