For the exhaust I would just go to your nearest custom exhaust place & get one made. to suit. You can buy off the shelf, but would be expensive to import. For lowering, it depends what the roads are like where you live. Personally here in the Midlands in the UK, I wouldn't lower it.
Yesterday I went to the nearest exhaust workshop . They told me just changer the muffler to straight, that's it. I think that just make sound loudly, nothing else.
If your after more power it will make the noise louder. You need to find a Stainless steel custom exhaust dealer. They will make a full system from the CAT back. You should be able to choose which size muffler you want & what tip ends to the exhaust you want. This combined with an induction air filter will release a few extra HP.
Hi Mike, Don't know were you are based but if you are close buy give Wayne a call below, very good exhaust man and he'll do what you want. J.A.C WAYNE JACKSON unit 7 plot 1 wigwam lane Hucknall Nottingham NG15 7SZ www.jacexhuasts.co.uk Tel:0115 9635556 mob: 07812 191122 Total price for full system £290 inc vat wayne says he will need the car for a full day if anyone is intrested please give him a call...........