When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The c6z shocks mentioned above from Cultrag are a good choice.
I just swapped z06 leaf springs into my base C5, and I went with DRM valved Bilsteins. I've only driven it about 100 miles so far, but based on that I am pleased with them. They ride very nice. so that's one more option for you.