U wont HAVE 2 change those things, but if u dont, then u wont get the most out of the engine and supercharger, and also, the more delicate parts of the engine may not survive for long...
I would have also expected that people would really want 2 have a big-brake conversion, but u will need 2 upgrade some part of ur brakes because with the extra power and the extra weight from the supercharger and its components will mean that u will need better brakes 2 stop...
If u have the money go for it, but get some more opinions from more people,find some people that have had it done and ask them exactly wot they did, wot problems they may have had, etc...