I was thinking about buying a Free Flow Air Filter, a BBR 175 Big Bore Kit, and a BBR Rev Box for my 03' Honda Crf150f. I dont know alot about stuff like this. I want to know if I should buy a BBR Exhaust System for it to, but I would rather just keep the stock pipe on my bike then spend $300.00 on it. What do you think I should do?