If your a classic rock player, I'd stick to your initial thought of a P90 guitar. Or a Custom 22. 22 frets will give you the creamier neck pickup tones often heard. 24 fret guitar changes the position of the neck pickup.
Hmm okay, what exactly is the difference between the customs that have the bird inlays and the moon inlays. From what I've seen the ones with the moon inlays were generally less than those with birds so I wasn't sure if there was a difference in them other than that.