Sorry, where are the links to the car?
I'm not a fan of lips myself on the oem bumper, but it really is personal taste. Carbon bonnet is again, much down to personal taste, I personally wouldn't want one because mine isn't anything like a track car, nor is it black, so imho it would just look out of place.
Ah, well now, regarding the spoiler, blitz do imho a nicer looking almost oem spoiler, evo-r do a half carbon version of it (but i've heard bad things about them on my350z).
There was a thread but it seems to have mysteriously disappeared, which doesn't do much for me trusting them, but here's what it looked like at least:
http://my350z.com/forum/exterior-and-in ... oiler.html