If you're actually going to do this or not, I think it'd be a good idea to add that second fan to your radiator up front to help with the cooling when you're sitting at lights, etc.
You might have to change your water pump arrangement along with the alternator in order to fit the compressor. It's going be a bit of work to add all this in... Also from what I've observed, there's been a few variances in cooling arrangements over the years. Your engine will surely run hotter with some loss of power as a result of adding the AC.
My X has factory AC which works fine (without overheating) but the radiator fans are on a lot when I'm not moving and I really notice the power loss when it's running. I almost never use it being in the upper NorthEast US as there are about 3 weeks in August that are hot enough to even consider kicking ot on. I'm sure your location is quite different however...
My 2 cents. Bob