Unless you are intending to fit the full Supercharger and injector upgrades, Exhaust etc, almost no point in doing the Cams alone. They are designed to work with increased aitflow of the supercharger and thus gains on their own with no S/C install are minimal.
The guys that put my headers and tune said they did not recommend cams.
We do camshafts but I do not recommend them on that motor. They take away a lot of power on the bottom end....kind of ruins the car off the line. At mid and high rpms they're great but not worth the sacrifice down low in my opinion.
Cams can definitely do what JB said, but it really depends on the grind.
I was thinking to have Competition Cams down in Miami do a custom street grind for me, but I could never find the spec's on the stock sticks to use as a baseline, much less the specs on the aftermarket cams.
So far, it seems that Schrick is the only company that actually makes performance cams for the M113 motor. The rest are just rebrands. Please correct me if you find I'm wrong.
You might want to track down a guy on MB world who goes by Havoc. He cam'ed an N/A R171 AMG (not sure who's brand) and outlined the mod in a thread he did on this and several mods he did to the car.