Triple parallel 28's. Fused claptons with 36g or finer. Even single-core claptons with fine enough outer wire can easily accomplish this. One of my favorite chewy vapes is 40 over single-core 24g. I do 10 wraps over 3mm for my series mod. Might wanna take a wrap or two out and try it that way on a 100w+ box. The most important thing is that you work some pretty fine wire into the build. Higher-gauge, higher resistance builds with lots of surface area. Claptons work well for this because of the self-wicking properties. The juice in the coil really brings the density up.
Also, shorties. It's all about the shorties. It needs a lot of airflow going into a tiny chamber with a reasonably-narrow drip tip. They really bring that full, lush texture out of those flavor builds. My favorite atty for the kind of vape you're talking about is the Snubnose. Simple 38/28 or 38/26 dual claptons churn out that texture and density on that atty. I usually stay in the range of .6-.8 because I'm running them on a series mod. You could probably just build a little lower and do something similar on a reggie box. Actually, you could get away with fused versions of those builds that way because the resistance can be lower.
Series mods are really great for getting that heavy vape, though. You've just got so much power for your surface area. The density on the builds you can do at 8.4v volts is just unreal. The vapor feels like taffy. Very smooth, bold and velvety. Even standard dual 28's or 26's can be pretty magical in something a bit more closed off... ...I like those builds a lot in my Sapor and even the Lush with the 510 tip and a row blocked off.
I'm sure any derringer-style RDA loaded up with a bulky, but fine multi-gauge wire build and dropped on a high-powered mod will get you there pretty easily. Those rigs just lend themselves to that really gooey, heavy vape. The vapor production is massive, but the clouds aren't huge. You get super-dense clouds that fall out of your mouth instead of the more common billowy ones that shoot 8 feet into the air. They pour out like a liquid, or maybe a drop of dye in water. I love running those kinds of setups.