dude get the kazuma and get a silencer for it. its gonna be a 4.5" silencer,preferably one with a small bore and as long as possible(measure it and cut it off just before the bend) when you get the kazuma you would know what bend i'm talking about.
and a lot of noise associated with the kazuma has to do with the fact that it was not welded properly.
i later found out that you can buy a adaptor at the muffley shop that goes into the kazuma exactly and goes over the stock exhaust pipe after you have cut it off. you can ither clamp this set up or after it has been put together mig or tig weld around both ends. it sounds smoother. thats how i am going to do my other kazuma(i sold mine and thats how we put it on this time)but i kinda miss it you will feel the difference low down,and hard above 6k!