Nismo conversion checklist?

[Exhaust]

Tried searching and I am either not looking hard enough or plain lazy. I'm trying to make sure I got my pricing right for my nismo conversion. I'm converting a 15 sport.

Front Fascia kit (not sure if this is the bumper as well???):

https://www.z1motorsports.com/front-...it-p-8198.html

Side Skirts:
https://www.z1motorsports.com/door-s...ts-p-7596.html

Rear Fascia kit:
https://www.z1motorsports.com/aero-a...ia-p-4289.html

I dont care for the headlights and the other goodies like floormats and everything else can come later. I think sub total before painting and install should be around $2.8k. I plan on doing most of the installs myself, outsourcing the paint. Is there anything else I need to know about? I remember reading something about the under tray needing to be replaced, is that true?

Thanks,