i suggest custom tuning with actual dat logging over any mail order or off teh shelf chip. although every car rolls off the same production line they all come out a little bit different. also how well maintained a car is makes a big difference in how it responds to tuning.
if you ask about tuning in the engine adn drivetrain board there are a few people around who can help get you pointed in teh right direction.
the ram air, if done properly does nto reach down far enough to grab any water(unless you like driving through 2-3ft deep puddles
). if you want to start with the air box mod it is very straight forward and will give you an immediate noticable gain.
if you want help getting started let me know, i live in ewing, so it would be a short drive for us to meet up some time adn knock out a few little things.
later
tim