I believe Zen~ only used fused quartz so the smoke tank was from somewhere else. Not sure if Spectrum tanks had smoke ones at one time, they don't have them in stock right now. Someone mentioned another way to go is get a plain Phiniac Phrosty tank and then getting it colored black.Provape sells the Stealth Kabuki - it uses the nautilus BVC/BDC coils. I don't know if it comes with a smoked glass. Here is a link.
Stealth Kabuki P3 thread tank by House of Hybrids