Bullet,I have been vaping for some time,as far as the rebuildables I only started doing that about four months ago,the Kanger subtank holds about 6mils of liquid with the prebuilt coil that it comes with,all you would need I guess is to make sure you got something that will fire the sub .57 Ohms I think the other one is a round 1.2 Ohms,don't hold me to this but the rebuildable part I suppose you could build the coil to whatever you would want it to be,1.0 ohms to 2.0 ohms just about any mod would be sufficient for that somebody correct me if I'm wrong.