for a panel filter, go with k & n, when i had my 1.4 almera before the VZR, i had a k & n induction kit on it, sounded quite nice to be honest, but dont expect to make any gains from either. if its just a 1.4, i doubt it would make much difference uprating the plugs.
On your other post, not everyone has a GTi, there have been a good few GA14s and GA16s knocking about, to name a few, tommos old 1.4, dales 1.4 tsi, covs 1.6 and a few others.
have a look at the members rides threads and you'll see some very nicely modded meras