The above companies are great choices....but...I did mine on the cheap. I got my K&Ns locally, then made my own smoothies with the instructions on the upgrade section of this site. I used Gates Vulco hose in the correct diameter, cut to fit. The clamps are a buck each at the local store. (They are all stainless) I liked the Gates hose material better because it is not shiney, they look more like they belong. If memory serves me, the hose cost around $25 for a 36" length. I gently cut them in a mitre box with a hacksaw.