Pretty much answered by others, taste and preference are all subjective to the user and what they want to get out of an e-cig as well as what juices they prefer. Like stated above on extra attachments, if the vivi hits your preference, get several more later down the road to keep other flavors in or keep in rotation, several rinsed, cleaned, and drying, while using a couple others in service and rotation, as well as a few atomizer heads for spares when others burn out on you, or if you want to dig into rebuilding coils, which is in the advanced stages. I will have to chip on having a couple glass or quartz style tanks like the Kanger ProTank if you prefer anything with cinnamons and citrus flavors, anything basically acidic, plastics and acrylics won't hold up to these liquids and crack or melt. Depending on your daily routine, or work environment, later, not saying now, but later down the road look at a unit that is more portable, believe the Zmax is a bit bulky, an Ego style 650mah, 510, or 808 style unit/kit are easier to carry around and bit more discreet, personally my suggestions would be the Ego decent power and vapor production on 1.8-2.5 ohm coil heads and can accept 510 treading on top of the Ego threading.
Whoever suggested the Zmax and Vivi as your first unit, my props to them for pointing you to an excellent first step to begin with, welcome aboard and good luck on your road to being smoke free.