If you're just looking for clouds, That has more to do with large airflow, large build decks, and plenty of juice flow. I might have a few suggestions for those...
My first suggestion would be the Griffin 25. The velocity style deck allows for large sized coils, and it's definately not lacking in air flow. I use the earlier 22mm version as my main device now, and the 25 just enlarges just about everything. I know the 22 is good for flavor too, so the 25 should be fairly good for flavor as well.
If you're just looking for clouds, there's one I'd give a shot..the Smok TF-RTA G2 or G4. This atomizer is fairly large and heavy, but it offers an interchangeable deck to allow a dual or quad coil builds. The G2 is also a velocity style deck somewhat similar to the griffin, but the build deck is slightly larger on the griffin for dual coils. The quad coil setup doesn't allow for large coils, but it's got four coils instead of one.
I'll admit, I haven't tried the Smok TF-RTA, and I am a firm believer of the Griffin for a very well rounded design. I will give one advice though, I'd recommend getting a small kepler type heat sink for under the atomizer. Not necessarily for the heat, but more for keeping the 510 dry. I've noticed with lower build coils, there is some spitback. And even though the spitback doesn't go throught the drip tip, it goes into the airflow.. and will seep down the airflow control ring and back on to your mod and 510. The kepler will stop that juice from entering your 510 and seeping into your device. That's just my suggestion though.
Hope that helps. do some research to see what others think. Anyone else feel free to chime in.