Need better s430 suspension, can I use s55
 

Thanks in advance for all your suggestions.. I have a 2000 s430 the motor was built by Renntech, the car is fast but only in a straight line... I hit a turn @ a good speed and the car is all over the road (I miss the s55 :()
I was told that I couldn't use the s55 suspension so I need to know is is possible to get an aftermarket setup just as good and where is the best installer in NY or FL... Thanks