Can't give you any advice about the a/c as I don't put any value on those systems here in MN, they just rob power...
As for the stereo, how much are you looking to spend? Pioneer and sony both have some good systems, I had a sony xplod in my old bug before I crashed it, and I loved it. I try to avoid speakers in the doors as they always seem to get beat up, and its one more set of wires going out into the door to go bad.
