To substitute those items above for safer options, yes-- Webby is right. Racelands are not a safe investment to make; A cheaply constructed coilover can make your car very dangerous to drive for the money you save.
If you'd like an Affordable coilover to start with, I can recommend Tein's Street Basis, Godspeed's Mono-SS, Megan Racing's EZ II Street, or Truhart. There are more brands that throw their hat into the ring as you go up the payscale, but these are the ones I see most often on 9ths.
Intakes for this generation of Civics in general aren't of much use unless you're boosting. The panel filter is pretty good for the most part-- unless you want an audible induction sound when you accelerate.
Civics tend to favor suspension/ handling mods in the thought-space of 'bang for buck'.