[RideWithDanger]

Rotofab is typically considered the best, but JLT has a new intake coming out in August if you can wait. Supposedly it's supposed to be the best flowing intake on the market.

The secondary cats are worth like MAYBE 5 horsepower, so on their own pretty pointless but with E85, CAI, TB, and a tune it doesn't hurt, but it's more for the sound than anything. Headers can yield a bit more but again, typically done for the sound over anything because bang for your buck it's just not that great.

I would suggest going FBO or at least all the mods you want at the same time, that's what I did. You won't have to have the car down for more time, or pay for retunes. Can also cut down on labor charges as well.