Questions on Exhausts and TwinTurbo

[ShinyaPGH]

I'm sure similar questions have been asked before, but I'm considering of getting FI exhausts for my 2013 NISMO. I'm also hoping to put AAM twin-turbo this winter. With that said, I want something right now that gives me more noise and a little more grunt. I just bought my NISMO in April, and it was really fun the first 2 months, but now I can tell the car could use a bit more power. The car looks a lot faster than it is.


option I have are:

1. put FI cat delete. either resonated or non-res Non-res with NISMO exhausts. has anyone done this? How does it sound? Do, cat back and twinturbo together in the winter.

2. FI cat delete and cat back exhaust now. and do twinturbo in the winter. Assuming putting exhausts on doesn't require tuning, especially without doing any forced induction, or not even cold air induction.

3. Wait till November for the factory warranty to run out, and do all of them together. cat delete, cat back, and twinturbo.

Also,
what other mods should I be considering, if I'm doing a twin turbo? I was told I should change the rear diff cover to the fin-ed type. Add an inline oil cooler. Maybe brake upgrades.

Any help would be appreciated.