Here are some options for you to consider.
Variable v/w battery is usually recommended over a "non variable v/w" battery. It allows you to adjust your settings to get a better "vape". Some flavors taste better at higher voltages than 3.7v
1. JoyeTech Ego-C Twist
2. Vision Spinner
3. Innokin iTaste vv v3
4. Innokin iTaste MVP v2
The first 3 are fall into the "ego style" category of battery (with variable voltage). They range in size from 600mah to 1300mah. The higher the mah the longer the battery will last between charging. The 4th one is a step up from an "ego style" battery in that it is a smaller box mod with a very big battery (2600mah). It will last many vapers a whole day before it needs recharging. It is probably one of the most popular batteries for someone upgrading from an "ego style" battery. Some vapers choose to buy one "ego style" battery as a backup and also purchase the MVP for their main battery.
I suggest buying only
name brand Joyetech Twist or
Vision Spinner ego batteries. BTW, "ego" is merely a type of battery, not a brand name. Buying "generic" ego batteries is always going to be hit or miss...mostly miss.
You will need to purchase a tank (the juice attachment) with the first three on the above list. The mini Nautillus, mini Aerotank or regular size Aerotank (all made of glass & all have adjustable airflow control) are very popular. The MVP Kit comes with a tank but it is not glass.
Why would you want a glass tank (you may be thinking to yourself)? Here is a great resource regarding "tank cracking" eliquid by ECF member Baditude:
Something Safe for Cinnamon and Citrus Flavors
