whats different(besides looks) between regular shocks...and coil-over setups?

 

Your front shocks are already "coil-over".... that's the stock 4th Gen configuration. The idea is to switch to a shock with an adjustable spring seat, so you can adjust the ride height of the car.

Stock front deCarbon coil-over shock (spring removed) with QA1 adjustable and Eibach spring):



In the back, stock configuration is separate shocks and springs. But outfits like Spohn Performance make conversion kits that allow you to use the QA1 adjustable height shocks in the back.

You can adjust the ride height to produce the best handling, or the best straight line acceleration.

http://www.spohn.net/shop/1993-1997-...oil-Over-Kits/

 

What difference would there be if I bought one of the Rear coil-over kits that you gave the link to...compared to buying these rear shocks and new stock springs seperate

http://www.summitracing.com/parts/HAL-TC2502P/

My goal is 400rwhp, although I do most of my driving on the streets, I see the track every now and then.

 

The rear shock you linked to is not an adjustable height shock, because its not a coil-over shock. That's simply a replacement for the stock shock. I have those in the back:



The coil-over conversion that Spohn sells is a shock with screw threads on the barrel, a seat that the spring sits on, concentric with the shock, and a piece to add the the upper shock mount to strengthen it and allow the top of the spring to support the chassis at that point, without damaging the chassis.

 

If you want a good street shock look into koni's. Qa1's for drag racing. Your not going to find a dual purpose shock, its one or the other.