Best posted in the Seicento/Cinquecento section.
Personally I'd not buy a Schumaker. It's just an Abarth with a horrible (and expensive to fix) ABS bolted on , and a few bits of tat to remind you of the psychopathic has been.
The 1242 lump is easy enough to fit. Doesn't give a lot more power, but the extra torque makes the car easier (and more fun) to drive.
Lots have been done. Full suspension, brake, wheel and tyre upgrade recommended.