Spark plug numbers and heat ranges.

Hello Everyone!
So I use a little nitrous on my F23. I have a few mods planned and will up the juice after I get done. I will go from a "75" shot to a "100" or "125" shot. My questions however are about spark plugs...

I currently run NGK BKR8EIX. I heard that BKR8EIX or BKR7E are the go to plugs for us Honda guys. What about BKR9EIX, is that too cold or something? What about BKR8E is that also too cold??

Also, I read that using iridium plugs is not the best idea with a nitrous car. So how do BKR7E's compare to BKR8EIX's?... Like as far as preventing pre-ignition goes. Im not too concerned with how long they last.

My last question is, what happens when spark plugs are too cold? Because, we all know what happens when they are too hot LOL. So if anyone can help me with these questions that would be great, also if anyone has experience with BKR8E's or BKR9EIX's in a Honda please chime in.

Thanks for reading everybody.

Well I tried BKR9EIX and R5671A-9 and both work ok. I just decided to run the R5671A-9's because they are cheaper for one and a nitrous guru I know informed me that there is no real benefit between iridium and standard plugs on a nitrous car.