I've recently bought an 2004 Astra SXI. Everything on it is standard at the moment and I would like some help with the best extras to get?!?! I would like it to sound a bit louder not 'boy racer' loud but a noise level where I can tell the difference. Would this increase/decrease performance/efficiency?

Would this mean a new exhaust system/induction kit etc? If so, which one?

I am new to all of this, recently out of univeristy so I have finally got the cash for a few modifications so any pointers in the right direction would be great!