Yes you will have to add cats, the factory cats will not work with long tubes. Just choose a brand that meets your budget and is of decent quality. I chose stainless power (they are the economy brand of stainless works, same quality, less warranty) and have had no issues so far. Most name brand long tubes with cats will run you around $1600-$1700, but you get what you pay for. Also most shops may charge anywhere from 500-1000 for install