Well, if you're asking my opinion, I say forget all that junk and get a supercharger. That's really not what you're interested in though, is it?
Intake and exhaust won't hurt the car's reliability at all, that kind of thing just increases the engine's efficiency. I would recommend against getting a custom exhaust system in your case, they're rather expensive and it probably wouldn't increase power very much without doing a lot of other stuff as well. If your goal is just to sound cool, you only need to replace the muffler.
The wheels, if you want the car to look good, absolutely get anything else, those hubcaps are not flattering. I don't know about black wheels on a white car, it's a matter of taste, but I think it's too much of a contrast.
There's a lot of forums that could help you find whatever you're looking for, and CarDomain seems to have a lot of KA9 RLs.
I think you mentioned a mesh grill? here's how that looks. I think the JDM headlights look really good.