The stock SVT Airbox/Snorkel and the SVT Header at the best zetec intake/header combo. A lot of regular zetec guys will swap the svt intake/snorkel and the header onto their cars.
when I had mine i made the mistake of adding an SRI onto my SVT before I did the research. But since i daily'd the car I rather enjoyed the sound of the intake combined with the exhaust I put on it so i didn't' care. Also never did get a tune either which I'm sure would have been a good idea but w/e at this point.
I'm pretty sure unless you went full legit filter in the fender CAI the stock is the best way to go
'04 VW R32 - Daily Driver / Winter Car
'04 Infiniti G35 - Summer Toy / because racecar
'94 Honda CBR600 F2 - Nice Weather Summer Daily