You will need a camber kit if your measured camber cannot be adjusted within factory specs.
Here are the definitions of Camber, Caster, and Toe.
http://autorepair.about.com/cs/generali ... 12201a.htm
The Alignment Tech will measure your alignment on a machine, and if your car's factory recommended alignment is out of factory specifications (measured in degrees), they will attempt to adjust the suspension using the adjustment bolts.
Since your car is really slammed, the factory adjustments cannot be tuned to the new settings. The camber kit replaces a part of the suspension where the adjustment bolt is. Therefore it can be adjusted to whatever the tuner wants.
A camber kit will save your tires if the tech cant adjust your suspension. Within 10-20K miles your tires will be all worn down on one side depending on style of driving. Pay now or pay later, or just dont adjust your suspension so low.
If your Tein SS suspension way too low and and other parts arent adjusted, understeer will be main feature of driving.