Welcome to GPF!! Great choice with the silvermist 99.
Post up some questions in the appearance section. From what I've seen the black headlights look good, but have varying degrees of quality. Seal around them with silicone and make sure your bulb gaskets are good and you should be ok. Of course the light output will diminish from the already poor stock lighting. I'd definately install HIDs or buy the new projector headlights from the group buy.
Usually wheels will be the first and biggest change. Tint, lights, de-badging (removing exterior emblems), tails or tinted tails, tips, grilles, hoods, spoilers, SD airdam, etc.
Good luck.
