The way i see it is that it depends on your budget, if you want to do it quite cheaply get a panel filter and smooth your airbox (do a search on smoothing it) with a larger air feed to the airbox.
Alternitively if you want to spend a bit more get an induction kit, enclosed or ones with heat shields are generally better to stop it drawing in hot air.
Have a search for a few different topics and see what suits your needs.