Chris,
Unfortunately I can’t give you any recommendations, but as you’ll appreciate there’s plenty of choice out there (too much?): Fabspeed, Designtek, Milltek, Bora, etc., etc.
The problem is that - sound-wise - one man’s meat is another man’s poison, so unless you’re able to listen to the modified exhaust under different speed and load conditions your choice is just going to be a shot in the dark no matter what others say. The degree of ’loudness’ is one thing but what you need to avoid is annoying resonances/boom conditions, especially when cruising at the legal speed limits.
As a safer bet you could consider fitting Porsche’s own PSE system which has been designed and developed specifically for your 718 CS, and at least you could probably find a car so equipped at your local dealership which you could assess for suitability.
Good luck with your search!
Jeff
