If youre going to fab your exhaust completely and are worried about smog, what I would do is get the cheap eBay ones if availible and make it so that every 2 years you can slide the OE manifolds back on (c'mon.. Takes what an hour ?) instead of forking almost $1k for Supersprint.

You have a C220? those also had an EGR pipe dumping into the stock header, so that's something else to include!