2003 9c1 heated, power seat install

I have a 2003 9c1 Impala and i want to install heated, power leather seats in it along with the over head console. I was wondering if anyone has done this before and what i would take to complete this project.

From what I've heard all the wiring is already in place, you just need the seat itself.

My 2000 has the wiring in place fron the factory.

I have looked at the connections available for the seats and the driver information center and they dont have enough connections for the extra features. I am looking for a schematic for the car to wire up the extra features.