The kanger protank 2 is popular and so is the Davide Glassomizer. Both have standard and mini sizes and take the same coils. Both are also glass. The Kanger EVOD is a nice non-glass tank for when your out and about.
UPDATE********************
So checking out reddit this morning I came across a post about the KPT2....
fella said to attach connect it to ego with the beauty ring all snug like normal THEN back off the beauty ring until it snugs against the base of the tank.
it works! snugged up the airyness just a tad and really thickened the vapor. A nice find. I would guess it closed up a ml to 2 ml gap.
Woot!
Illegal to vape on a plane, but it can be done without being caught. As for all your gear, they don't care. Be sure your liquids are in a ziplock. Empty your clearo's before you board though. They will leak. I wrap mine in a paper towel Ina ziplock.