If you want clouds get a mechanical mod, and a good battery. Depending on how you set up your coil it could blow insane clouds. It is safe to use 18 mg nicotine juice with an RDA but you would get a crazy buzz, i went from 18mg to 6mg when i switched to RDA's. But yes a VTR will work, and when you build your coil make sure the resistance is 1.0 ohm or higher.