Back when I had more time than money (or sense), and because I started off with older sixties cars and trucks, I would spend time creeping up on the right gap setting by starting a little low, then working out to a little higher than spec.
I always found a sweet spot with whatever engine combination I was working on, and it was usually within a couple of thousandths of factory recommendations. But with updated ignitions, it was usually on the higher side of stock.
That said, once I got more and more V8's with harder and harder to reach back plugs, I pretty much changed to a "set it and forget it" mode. Basing it on my own experiences, I'd go with stock to a couple thou bigger and try never to touch them again until it was absolutely necessary!
But hey, back then it was all fun.
I could lean over a hood all day long and not end up with a sore back.
Sorry for the old whiney story. Meant to say you've got good advice and looks like you're already on the right track. But as you see, you usually go with the ignition, not the heads by themselves. So better to go with somewhere in the Duraspark range.
Let us know how it works out and the difference (if any) between the larger and smaller gaps.
Paul