Kanger Mini Protank 2 is the best one to start with. Easy to care for and the coils are very inexpensive at Fasttech.com with free shipping. You can get them on ebay with free shipping. The other one is the Kanger Protank 2 with the Aero air control base (sold separately).
I have been using both on Innokin Itaste VV Version 3 and Innokin MVP. They are easy to use, clean and well made with the pyrex glass that can handle any juice.
I used to smoke a carton a week for over 25 years. Started vaping a little over 4 years ago, and after 9 months got down to 0% nic, make my own ejuice with 100% VG. Its about the flavor now.