Homoet pipe is the best for that set up. This is a great city machine where you need acceleration over top speed to keep the cab drivers from running you down. I suspect with taller gearing the carb tuning may become more problematic. Big carbs don't like to lug out the low end, and you have to really work at finding the perfect jetting combination.
Running peds in Boston go for more than elsewhere due to the generous moped laws, abundance of college students, and heinous parking and car costs. This is a GREAT deal for this locale. I have seen stock peds sell for $750.