I used NGK BKR7 on my SR20 as well its used on 300zx's. I had no problems with them. They even took some detenoation when one of my injectors gave out. Looked fine after.

I have heard bad things about the iridium plugs on FI cars but then thats what the mitsubishi EVO FQ400 uses so it's hard to say as that is a serious import beast. I think with the iridium there is less room for gap errors/inconsistancies.