Spark plugs selection

[PLP]

Well, which one to pick?

There are several different models.
Anywhere from OEM like to "double electrode/high ignitability"... so what are the opinions?

I experience this RPM related chirp. It might be the spark plug, so since I will be doing it, maybe just replace them.


As for the chirp.
Happens when at low rpm under load. It goes away when engine is hot. Or I cannot hear it.
Each gear. RPM related (increases in frequency with RPM).
Does not really happen at idle or when revving the engine. Hence I thought mounts or such, but that would not make a chirping sound (like one squeak or so), right?

Overtime it became stronger, meaning started months ago with a few small chirps that would go away quickly, now it is more pronounced and stay for longer.
Yet, goes away when the engine gets hot.