Probably
fasttech. I have the brass v3 and I'm happy. I have to admit the The stainless chi is better looking though. For a tank I highly recommend one of the kayfun clones. The small chamber and air up under the bottom of the coil makes for a stellar vape. If you don't mind a metal drip tip, take a look at the rocket from fasttech.
For batteries, I've been eye balling the Panasonic CGR18650CH, but I mostly build around 1.1 to 1.4 ohms. If you plan on going sub ohm then you might want to find the 30 amp sony.