A locking diff is good for straight line stuff. Don't expect too good of performance in the twisties though. They're known for being unpredictable upon exiting a curve....They could lock up early and under full throttle acceleration coming out of an apex, you'll have lots of push.
If you're just doing the light to light stuff....it should be fine.
Yes, they're noisy.....but Cobras aren't made to be quiet.
This unit will work in your car if your axle splines match the diff splines....for instance if your diff is 31 spline and your axles are 28....it won't work.