Yes to the defroster and all other doors. It's you ride so I say do want you want with the A/C. As Leon noted, you can't have to much cold air. I would suggest you buy the biggest condensor that will fit as that's where the heat exchanger is. Most of the units I've seen don't let you pick and choose the evaporator unless you change model units. BTW, insulate the fire wall and toe boards. All of your ride if you can afford it. Don't go the cheap route either, use the good stuff like "Dynamat" or "Lizardskin". That's what keeps the cold air in and the hot air out.
