Gday mate, at the end of the day its your money and your decision. From what you are saying though you arent really interested in a couple of percent power gain at all and are really only after sound. In that case in the same position id just go a cat back. Just personal preference but i have something against tacking a muffler on the back of standard exhaust. I would say dont even worry about going brand names just for sound, id go to a reputable exhaust shop. That way you can tell them the sound you are after and if its wrong a lot of shops will simply change the muffler for you. Headers will give you a couple of percent but will set you back a bit. A custom press bent steel exhaust probably wont cost more than 220dollars and will get you a nice noise. All that extra money you could spend on full stainless and headers and cat and everything will make some difference to noise but mostly just bump up your power in small increments. Seeing you are after noise, just go a catback then if you decide you want more later you can add it. A lot of people get headers and dont even like the noise of them anyway. Let us all know what way you end up heading..