Alpine is great, but right now Im rocking a panasonic that is pretty decent. Figure out what you want from your headunit and go from there. I wanted one that played MP3s and WMAs and had an aux line in, so I settle on the one I have.
Springs from a TJ 4 banger. They gave me ~1" drop in the front. And I swear Im one of the few xjs that doesn't have leaf sag. It still sits as high in the rear as it did stock.
Sounds like a good project. I myself went with a larger front swaybar, but kept the factory rear one. What it does it control all the weight in the front wanting to rotate, while allowing the rear end to rotate more (producing small amounts of oversteer). That, along with my drop springs...