[Spark plugs]

Hey guys so im getting some parts together to do a tune up and im doing research on spark plug options and i cant seem to find a specific one to go with that isn't bookoo bucks 

Any help is appreciated

[91 skyline gtst type m]

What do you mean ping? And it was actually 92 octaine that was a typo and yes im in the us

I dont know much about cars so i have no idea where to begin looking

 

[91 skyline gtst type m]

Hey guys i just got my dream car last week. Its a 91 nissan skyline gtst type m. Ive beem saving for over 8 years to get this car and im so excited i finally have it. Im looking forward to many years with it. 

Unfortunately today i filled up my gas tank with 91 octaine ethenol free gas for the 3rd time since ive owned it and after i left the gas staion everytime i come to a stop at a light or intersection my car will idle out and die. I can start it right back up but the ilde is way low like 300 to 400rpm.

Can anyone help? 

Im not sure if this is the right place to post this question. Feel free to tell me and i will move it to the correct place.