Csx 4000 - suspension upgrade

[OROBBE]

Hello,

I own a CSX4000 since 3 years now (I was very lucky I found a rolling chassis that had been stocked during 10 years by the first owner). I installed a Pond 482FE all aluminium engine + TKO600.

The car works perfectly but factory suspensions are very bad, too soft and start leaking.

What I'd like is to replace my current suspension.

Any manufacturer/models recommandation ? I use the car on the street and on track and I absolutly want firmer suspension than I have...

Thanks,

OliveR