If you want your bike fast without increasing the displacement you're gonna be trading your take off power for that fastness by means of gearing. That means you're gonna want to rely on pedaling from a stop. Definitely get a tiny freewheel, like a 16 or 17 tooth. They're only like 8 bucks. That way you can trade all your takeoff power for top end speed and still be able to take off halfway decent. Trust me, you'll love it!
The jammy pipe is quite a bit better than the stock pipe. It sounds wayyy better and will give you much better bottom end but for a few bucks more I would've gone with either the Tecno Boss, or even better, the Tecno Estoril. I'm not really sure how ideal the Estoril is on a stock cylinder though.
Good luck! I remember when I caught the bug!