i got the RPW headers in the end they will be much nicer than any stock headers and sound good to. i think the outlander headers could have been a good idea if i wast going to use an aftermarket ecusome outlanders which came with the 4g69's came with catless headders. make your life easier and use that.
an aftermarket exhaust isnt going to make much difference in the car.
if you do use the catless headder off the outlander, move the second O2 sensor to AFTER the second cat to prevent check engine lights.
i used the factory ch lancer exhaust (front section to second cat will go straight on without mods).
i blew my rear muffler and ended up putting a straight pipe through the rear muffler, was loud and backfired heaps.