offset rims and lowering awd cts
 

I`ve been told bc racing has the best coilover for my awd cts. does anybody know anything about lowering with this method and how it will affect my ride and my steering performance?
also I want to put some fat ass rims and tires on the car. its a 2012 cts performance 3.6 sedan. I need help sizing offsets,rims,tires. I want this car to look filthy but don`t know where to start!
can anybody help?