Both could work. It all depends on what you need.
I would say a turbo is almost on/off and a centrifugal supercharger is more linear, you feel the boost coming.
Please contact this guy:
http://bgturbokits.com/storebg/
He does custom turbo kit if you select this way otherwise, you need to join the turbo forum
http://www.theturboforums.com/smf/index.php