Eaton makes a lot of OEM superchargers for ford, GM and mercedes, as well as aftermarket superchargers for magnusson and TRD. A lot of their kits are well designed, but are application specific. Eaton superchargers have a good reputation as being very reliable, good for 100,000 miles. Change the nose gear and go another 100,000. The boost on these are almost instantaneous when you mash the gas (I have one on my truck)
This is nice write up on the TRD supercharger: http://www.gadgetonline.com/Super.htm
I thought sombody attached an eaton m-60 a while back on this site. If I remember correctly it was mounted on the passenger side. I don't remember if the setup worked well, but it was neat to look at.
B+M is now Holley, Weiand is a seperate company. Two slightly different philosophies on rotors. One uses teflon tipped rotors the other uses tighter tolerances that they can get away with because of a stiffer casing, at least thats what there marketing guys say.