hey guys, i have been looking and reading about rocker's (dont tell me to install a cam).
my questions are witch one is the best for my car.

N/A with headers down pipe, and intake.

i found those
ZZ Performance

ZZ Performance

what other parts should i also buy?
will i feel a little difference?
how hp will should i be expecting?
to be more on the safe side what other mods should i do at the same time?

thanks