Rack and Pinion:
They sell a kit that you can rebuild your rack. It will come with all the rings and seals. Here's the problem... You will need to pull the rack off the car inorder to do this. If you want to spend just a few more bucks, you can get a rebuilt one already assembled for you. All you have to do is put on the outter tie-rods and your done. IMO: since you will have to pull the rack anyways (to rebuild or to replace), it would just be easier and take less time for you to buy the rebuilt one. Then you will have to get it alligned. I did it to my brother's car and mine. The rack cost me about 100 from Autozone (there are two kinds-stock, and a sport one. The sport one is a little stiffer) and depending on where you go, the alliginment will cost about 50 bucks.
A/C:
ummm, not sure about that one. Make sure the vent aren't closed
