I went through the install this weekend. It was the warmseats waterproof heated seat kit. Runs about $85 on the warmseats.com site.
I think it is pretty basic, though I am glad I don't do upholstery work for a living.
To do a car again, I would not get the waterproof version of their heated seats. I think they heat up slow, only because they are incased in a insulated pad already and the heat takes that long to penetrate. The only negative I had was that the cord to the switch was too short, so I ended up adding wire to run the wiring properly.
Stephen