Actually its possible to put togather an ic pipe kit for under 200 dollars, but it dosen't look pretty. I work at boater's world and there we sell exaust hose for boats. Its capable of handling a crap load of pressure and heat, comes in any size from 3/8" to 5",and is easily bent. Only down side is that you would need to make a tee fitting for the bov and it dosent look nice at all. Then again the inside is non ribbed. 8 feet of 3 inch goes for 145 dollars or so.
http://www.boatersworld.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&catalogId=10051&langId=-1&productId=13004504 Here is the hose, we have 3 inch in the stores but my company is ghy and dosen't show it on the web but here is a pic