Makes it easier if you post your car, instead of me having to look in the corner of your post. How much cash do you have, what are your eventual goals with the car, predominantly street or strip, etc.?
Seeing as you only have vs exec up i'l assume it's a 6.
Best system would be a single 2.5 inch mandrel bent system with whatever your choice of headers(different people will tell you different things) I've only ever had pacemakers and i can't fault them. Make sure you shop around a) for price and b) to see there work as you dont want an exhaust which just drones at high speed. Depends on where you go and who you know, budget $1-1.5k for someone else to do the work for you or if your handy with cars and you have kind mates even less.