OK I have a little valuable input for you. I typically use the standard autolite 64 because they are cheap, available and read well. I tried a set of denso, they were certainly nice and make you feel good but there was no performance difference. The denso plugs seemed to wear down faster.
I have used NGK in the past but it was before I paid attention to anything. I'm sure they are fine plugs.
I used to buy gimmick plugs, and iridium and platinum will last longer, but as a general rule I like to use standard copper plugs, especially if you are tuning into a hybrid. You will want to change plugs a lot when you make big changes for a fresh read. Plus copper plugs are cheap, always available on the shelf and I like to change plugs about twice a year on general principals because it keeps you in the know on how you are running, rich, lean, oily, coolant-ee.
Some guys go one step hotter and gap them out more which seems to work good for EFI (for example an autolite 65 gapped at .45), but I have found the standard heat plug gets the best read when you look at the strap to check heat range.
At one point when I first got into my hybrid and I hadn't messed with jets yet I had a pinging problem but I was able to cure it by running autolite 63s, which were one step colder than stock specs, gapped a bit smaller than stock. I picked up that trick on an old Mercedes forum.
