Believe it or not, I have seen a few people put 99-00 Si headlamps in place of their old ones. Doesnt look too hard to do either, the only thing I can see that would be difficult is that the front bumper may need cutting slightly for a seemless look. Shouldn't be too hard though IMO.

Tell you one thingthough, those headlights and the 96-98 front bumper are a helluva good looking combination!