If you want gains you're going to need to get Hondata Flashpro first and the only intake so far to consistently show any type of power gain over the stock system is the PRL CAI. Then make sure you have money set aside for a tune. Most "easy" gains have been on the exhaust side from what I know. Perhaps look into a down pipe, exhaust, and a tune with flashpro first.
Heres a DIY article showing the install and said parts: