An alternative option to an off-the shelf systems like the Milteks is to find an exhaust fabricator and get a stainless one custom built to your car while you wait (or while you go off shopping). You tell them your noise requirements and they will fit appropriate silencer boxes to fit your needs. And you also usually get to choose from a selection of different types of tailpipes.
I don't know where about you're based but there are a few reputable companies dotted around the country.