upgrading my system

[spectroff]

I'm a new w202 owner. I'm deliberating how to set up my system. speakers are a amust, but I'm not sure about the head-unit. I'd like to keep the stock look, but don't want to sacrfice clarity/power.
Does anyone know the specs on the stock hea-unit?
Any input on advatages/disadvantages of replacing the h/u would be appreciated.

[audiophile]

if your looking for better sound you have to replace the head unit. :D