If you are going to kit it, then you can "get away" with using a PA50I motor. However, you will need to modify the variator and then install a PA50II ramp plate and variator weights. Please see the wiki section for PA50I/PA50II differences, etc.
The Leovince pipe is current not available - like a several month manufacturing delay.
You'll need a PA50II carb, or you'll need to upgrade to a larger carb. See ebay for treatshq's shop.
You'll most likely have to modify another pipe (not made for Hobbit's) to fit your bike.