Supercharged sparkplugs

Oh yee supercharged brethren,
(other supercharger owners)

I was wondering what sparkplugs are being used with the supercharged motors. I know, when the Alpine kits first came out, they included cooler sparkplugs (NGK BCPR7ES). Since then, Alpine has stopped including new plugs in the kits. Was this because the cooler plugs weren't needed, or are they just getting cheap with the kits.

Is there a performance gain or loss in using the cooler plugs?

I was thinking after a year and 30K+ miles, it might be time to change my plugs and was wondering which ones to buy.

Thanks for your input,
Kirk

Well, for Arizona I believe it will increase your performance, but up here I was told that I didn't need to do that. I am still running the factory plus at 48,700 miles 2K with supercharger and no problems.