Can I offer you some sincere advice?
It seems like you want a comfortable 911 (inside) which will look from the outside to other people like it is really hardcore.
If that's what you want to do, then that's fine, no problem with that. It's your money after all!
But, personally, the fact that I would know that the car is really a C2S and not a GT3 would make all the difference to me. I care about what I will know far more than what others might think.
Honestly, it seems to me that, deep down, you want a comfortable 911 (e.g. no -20mm for ride comfort reasons, rear seats for practical reasons etc) but you simultaneously care so much about what strangers on the street will think that you are prepared to alter the exterior to impress them. It's a bit superficial.
I know you've already said that, in your eyes, fitting an aerokit makes the Carrera look like it should look but the example you quoted proves my point. You referred to liking the old whale tails. Back in the 80s, they were fitted on the Turbo models not on the Carrera! So the example you've given still shows that you want a Carrera on the inside but on the outside, you want it to look like one of the Turbo models you saw in your youth not how a Carrera looked before or how it should look now.
I would suggest that you decide what kind of car you really want - comfort OR hardcore - so that there is harmony inside AND outside.
The 997 GT3 IMO is a hardcore car that is perfect for track use but which can be used on public roads. Having a GT3 skin on top of a Carrera's innards (which is essentially a road car) makes me think of one image only: boy racers in their Evos and Imprezas.
I agree totally with what you said about people liking the appearance of the GT3 but not liking the aerokit on a regular 997. It is completely inconsistent on their part. I have written previously to that effect (as has 69bossnine).
I respectfully disagree with Le Chef here (and I agree with you) regarding the 'wannabee' comment. A wannabee by definition is someone who can't have something for some reason (e.g. money) but wants to imitate it anyway. I agree - if you can afford a C2S with aerokit, we're talking about nearly GT3 money anyway so, in my book, that's not a wannabee.
It is however pretending to 'have' something you don't have for the reasons I gave previously.
At the end of the day, my comments don't matter at all. What matters is YOUR enjoyment. Once again, hope I haven't offended you by some of the more blunt comments I may have made. Just trying to give you a constructive view.
The bottom line is: it's YOUR money so you should enjoy it however YOU wish!
All the best. I'll shut up now