*Opinion alert*
With regards to the exhaust what are you after? For me get the pre-cats gutted or replace for a pipe without pre-cats and get the central resonator chopped out and a straight pipe welded in. Nice noise on a budget.
The nicest one I've heard in my limited experience is the JC Fabweld that Neil who commented above has.
There is next to zero bhp to be gained from the exhaust with a couple of bhp from a 2.75" diameter full system from JHM for example. With import changes this is very expensive though.
Again Neil did a massive amount of research on exhausts before choosing the JC and money no object it's the one I'd get
Link for JHM pre-catless down pipes
https://jhmotorsports.com/shop/catalog/ ... -1375.html
Just as an example of an alternative to using existing down pipes and gutting them
