I have tried looking but cant seem to get a decent answer,so here goes ..................(I have a wrx wagon)

1.what are the best spark plugs to get?

2.whats the best panel filter to buy for noise and bhp?

3.is the standard fuel filter the best ??

 

Ngk platinum.
Depends if induction or panel filter as panel filter won't add any noise. And really not noticable bhp either.
Standard fuel filter is fine