2-port Pinasco 177cc cylinder kit for early Vespa 150 Super

Hi from Australia. 

I have an early 1967 VBC 150 Super with a 2-port motor. I want to fit the 2-port Pinasco 177cc cast iron cylinder kit. I also wish to use it with a Sito Plus Exhaust. Should I use Sito's PX80 or PX200 model for the bigger 177cc cylinder?  I believe I have to cut off the front mounting lug of the Sito. Can I still use my centre stand? (I have 8" wheels).  Are these performance parts suitable for my scooter?

With thanks