this has been covered a few times... and a lot of ppl say do this and do that... not worth spending a thousand bucks, etc.
do it right the first time... just get a mugen intake...
i have been driving my car stock as a rock bought second hand... come time to install my mugen, i realised that the previous owner actually removed the resonator box in stock intake... installed my mugen and response like no tomorrow! have had no regrets spending that thousand dollars...
and i'll have to dig up my dyno sheets, but compared to 'stock' and 'mugen', i got 5 kw atw extra. most importantly, response was heavily improved.