I would go with the exhaust and filter first. Get them together and you will be finished making your Blaster breathe easier. You will also need the jet kit. Then go for the reed system and other mods like that. Go with the basics first because the other mods like the reed system give you a lot more power if you have the other things installed first.
I would say that the Toomey B1 kit would be great for you as it comes with an airfilter, jetting kit, and pipe/silencer. This pipe will also grow with your modifications (but it is not the best pipe for a big bore engine from what I have read).