These cars are capable of being extremely loud... if that's what you want, however with a system as loud as you're describing you'll never hear your radio!
Something like an ark true dual or invidia gemini (or many others cobras scorpions etc) will give you the dual look you're after, and when coupled to decats or HFCs will be plenty loud enough for most people, but whilst maintaining the lovely tone of the V6... personally that's what I'd aim for...
Another option are the japspeed boxes, if you really want loud, get a non-resonated japspeed But again, these are super loud!!
Also just be weary that your car may not pass the MOT with decats, just worth baring in mind... Although HFCs should be fine if the car is warm when tested so it'd be worth getting to know your MOT guy in advance, they also make the exhaust considerably louder than stock cats and a bit more "fruity"