Exhaust options

I'm interested in doing some type of exhaust for a 98 Aurora. What options are there? Could I get a high-flow cat, bigger piping, aftermarket mufflers, and be okay? I know our cars are touchy, but I don't know how touchy. I've been searching but can't seem to find any valid info. Please let me know!

Thanks

Topic covered well with lots of pics on Aurora Club North America site.