One thing you'll run into with the bigger octas is that they might not be very stable on the Dlite-4. My Dlite-4 strobes are several years old, and maybe they've improved the mount, but if not, anything over 135mm (and maybe even that one) won't be very stable. The Bxri and RX strobes have sturdier mounts for the bigger octas. With that said, the ones you mentioned are all nice but have different characteristics and serve different purposes. I'm surprised you didn't throw the 70cm Deep Octa in there too! I happen to like that one for head shots, but I also like the Kacey 22" BD that you have for that. Grids for any of these from Lighttools will be very expensive. So that's something to consider. The deep octas give you more directional light. They all provide very even lighting across the swath of light they produce. I find the 100cm deep octa to be very versatile, and while I haven't shot cars with it, I've used it for everything else you've listed.