Ok first off what do you want the car to do? If you want more low end grunt then a supercharger is better. If you want more high end power a turbo is better. It's really best to know how you will use the car and what your preference is. an intercooled turbo will give you more power but where do you put the intercooler on a Jazz?
This link should explain the differences for you.
http://www.turbocalculator.com/turbo...ercharger.html
This site is also helpful.
http://auto.howstuffworks.com/question122.htm
Of course you have to find out what is avaiable for the Jazz. The turbo lag makes the car unsuitable for autocross as it can come on at the most annoying times and cause you to spin out.
It won't be cheap to turbo or supercharge the Jazz. plus you will need to (in most cases) modify the exhaust. Great fun tho, love teh power when the turbo kicks in.