What you need to know is head tube diameter and rake. I don't know if the CAAD9 has a tapered head tube or not, but that's critical. Rake doesn't have to be exact, but it should be close to original to perserve the same steering characteristics.

Time does make a good fork. ENVE might still have some on sale, check the 'dark deals' section of their site.

However if you're not racing, you don't truly need a high-end full carbon fork like that. Thus my earlier suggestions to look into buying or trading for a CAAD9 ultra or premium fork...