Since you had both pipes, would you recommend going with just the CS downpipe? I have the MS CAI and MS CBE. Love the sound of your Speed3, sounds siiiiiiiiiiiiiick! (rockon)
IMO get a DP to go with your CBE and CAI for the best combination and power levels if you don't plan to modify the car too much. I get good mileage when cruising, I love the sound of the car and it still goes well enough when I need it to.
Enjoy your ride what ever you choose.