My advice to you is enjoy the car N/A for a while. Far to many people just go right into projects before they ever really learn the feel of the car. The stock ka is a fun little motor, enjoy it. That way when you increase the power your already familiar with how the car handles.
This is the Ka-T section of Nico, great stuff here.
zeroforum?id=170
This is the Ka-T info sticky. Everything you want to know about Ka-T's is here. Pretty much any question you have has already been answered, in this thread or elsewhere on nico.
zerothread/99647