im going to turbo my z6 to. i think im going to use the greddy kit mainly because it is pretty complete and you can rebuild the turbo if it breaks. a lot of power can be found with the little d series motors, except for the non-vtecs. to learn more about that stuff, try turbod16.co or try here
http://www.beesandgoats.com/boostfaq/g2icturbo.html for some more turbo info. sorry to hog your thread, but can a ball-bearing turbo be rebuilt?