yes a aftermarket exhaust and filter will improve your performance. Jetting will be required with any aftermarket exhaust. I have never used the HMF, so I can't help you there. But from reading the Ultra Quiet QS1 Eco-System might be what your looking for. As long as you don't hammer the throttle it want be to bad. I use the Uni filter and it is a big upgrade over stock. Also it is half the price of a K&N. Both are great filters, but for me I think the UNI is easier to maintain then the K&N.