I read the article about installing the Kilby onboard air....seems pretty straight forward if you buy the bracket kit from him. Mounts where your current alternator is now and relocates the alternator underneath it. You will need a new belt to acount for the longer length. This is assuming you have AC....if not you can mount the compressor in the factory AC location. The price on the bracket was not cheap.....$150 US I believe.
The only problem with that is that I believe they changed the configuration of the various pumps etc. between 2002 and 2003. I hope I'm wrong because trying to mount a York compressor in the stock A/C pump position would be a task to put it lightly. I never paid enough attention to my 2002 so I just don't remember if it is the same or not.
Yes the Kilby OBA fits the Rubicon just fine. I've had mine on since october 2002. I have A/C. The only thing that was a surprise and that they don't tell you about is that the OEM belt tensioner is removed and no longer used. The belt is now 100% manually adjusted. A little bit of a pain. I wish they could have designed it to still have the automatic belt tensioner. Overall a nice kit. Easy to install