It depends. I'm not sure if this was just an 04 thing, but somewhere along the line they switched the wiring completely. The beginning 04 model has the same wiring and plugs as the 97-03, then later they switched to using the class2 data for the heat switches.
Basically it depends on your skills and what you're willing to do. I've got dual heated seats with 180 fold both power with 6 way lumbar in my 2002 so it's possible.
If you can post a picture of the connector and wire colors, I can create a wiring diagram that you can use. You might need a plug from the 05+.
As far as the airbag, I didn't think they had actual airbags. At least the seats I've seen use a detonated seat belt tensioner and that's it, but maybe that's an 07 thing? If your current seats don't have it, then there's probably not a way to safely adapt that.