Polini 177 kit for px125, year 2000 model

I have a totally standard PX125, year 2000 model and would like to upgrade it to get a bit more performance out of it. I have been told to get a Polini 177 kit and a Sito Plus exhaust by a fellow scooterist.
In the SIP catalogue it says the Kit should be used with Sito Plus exhaust and 24er SI Carburetor. What kit do I need to fit when putting on a Polini 177 kit? Also, is there any exhaust out there that is slightly better than the Sito Plus, but around 100 euros? Anyones advice would be greatly appreciated.
Forgot to add that i am a total novice and would like to know if there is much maintenance involved if the kit is fitted. The scooter is used to daily to commute to work and back - about 25 miles a day.

[ Message edited by smcelney on 27.04.2002 ]

thanks for your reply. Should I put a new Carb on? If so which one?![:)]