This is a trick question right?
If it came to the point where I could only
buy eGo specific atty's, I would get LR eGo Mega Type-B
tank attys. When they wick properly, they have been the best Ego specific atty's I've used.
For dripping, I prefer a LR 510 or LR 306 atty. IMO they are far superior in vapor production, throat hit and flavor.
Another thing to consider if your going for vapor production is your
juice mixture. Higher VG content will produce more vapor. You could take a brand new eGo kit out of the box and get mediocre vapor production. You could then take the other atty and drip VG liquid and blow out thick, dense clouds.