Okay, you could search this forum for power adders for the NA and possible turbo swaps (what you need if you plan on making decent power)... both have been well documented on this site, just search for em.
if you put an intake on your NA ill sound just beastly (a good thing), as far as power, the NAs have headers, intakes, and exhausts... but not much else
i had my NA going pretty quick because i tore out everything i could get my hands on, but now im getting a jap turbo swap (cant wait)
and as far as the scoops go, the ones on the sides are more functional than the aftermarket ones you see all over... at speed air goes into your engine bay via side vents and from under the car and it exits through the top vents. to have something pushing air in the opposite direction of air flow will cause disturbances in the air and decrease/negate any cooling effect most people think they are getting. to sum it up: they are for looks