Any mods you make, wont make a difference on the engine performance, unless it has a remap to compliment them, and to make full use of them
Therefore, any induction kits/Exhausts are purely for the delight of your ears..... more roarrrrr
So what kit you choose is all down to personal taste, go on youtube, theres plenty of americans that have fittest various combos, see what ones you like the sound of best...
Myself, I have an AEM cold air induction, K1 exhaust, and newly fitted plenum spacer, however none of these mods will take effect performance wise until I have a remap. Untill then, it just sounds lush!