First off Welcome!
Secondly search each section.
There are numerous threads on these subjects to the point they have been beaten to death.
Here are some threads to look and ask questions.
[Official] "Which Exhaust Should I Buy for My 370z?" Thread
the370z.com's Exhaust Quick Reference Guide
370Z Exhaust Sound Clip data base
The most popular Intakes are "Stillen Gen3"
The most popular Exhausts are "Fast Intentions"
The most popular Engine tune is "UpRev"