I'd just use the clutch you already have, till you need one. When i installed my diff, I didn't even look at the clutch...I'm still new here but I have similar plans. If you don't have one i'd say get a Rear Sway Bar in general. Just did that mod and it helps a heck of a lot. Power Items from what I've read are CAI, Cat Back Exhaust, then Turbo. From what I've read though if you put a turbo on or build the motor you are going to do have to put in a performance clutch. While you are that a differential wouldn't hurt.
Yea, you could replace the oem one w/ a performance one, my thoughts are, Why not use the one you have till it needs replaced, its there use it. I'd get the turbo dialed in & drive it. If & when you do a clutch, I'd also add a torsen. btw there are other suspension mods I'd do no matter what power you have.So its not a definite you need a performance clutch when you turbo? Just when it goes out get one? Interesting I have learned something today.