To build up or not to build up
 

What up I am new to this web site, and I have a question about what to do to my Bonneville. I have a 1999 Pontiac Bonneville SLE and I would like to supercharge it. The car has a 124,000 miles and runs amazing. But I am not sure what to do, either to build the series II engine up and but a kenne bell on it or to buy the the series III with the supercharge on it already and mod it from there. What is better to do because I am hearing the it is better to build the series II up and Whipple it or Kenne bell it.