with regards to cold air what brand would you recommend? how much and where can i purchase it?

i know that there are immitation in the market unfortunately i don't know how to distinguish between the fakes and the original... (kakahiya naman kung fake ang mabili tapos ang presyo niya ay original diba... )

list of brand that i've seen so far... (* need for speed)

INJEN, AEM, K&N, APEXi, ICEMAN, STILLEN, NEUSPEED, WEAPON R, SIMOTA, DC SPORTS, etc, etc... so many brand nakakalito...

for me the important factor is the quality of the product, warranty, and the cost... thank you