Another vote for the Subox kit. Lots of flexibility and room to grow in a mod that can be had for $60 if you look around a little. The rebuildable deck comes prewired with a 0.5 ohm coil that worked for me for about 6 weeks of hard use. It's easy to wick, and one of the easiest decks to rebuild on. So it's a great intro into rebuilding when you are ready. You get two coils, one subohm 0.5 ohm, plus I think a 1.2 ohm? And the rebuildable deck. So you want to buy a 5 pack of coils, at a minimum, so you don't run out of coils and if you get a dud you aren't in a panic and running to a gas station for a pack of smokes
Back up everything. I like 18650 batteries because I don't like the idea of having to pay for regulation electronics with each battery. I bought Samsung INR 25R 2500 mAh batteries from Illumn.com for 5 bucks each. But you need to back up your mod and you should back up your charger too. You might spend extra for a nice charger but you should at least have a basic but reliable and inexpensive spare charger in case your main charger dies. Same with the Subox, if you like it, buy another one sooner than later, or buy something else to back it up.
The secret to quitting smoking is to always have a working mod, 24/7/365. It can take a lot of back up to get there. That includes a minimum 2 days supply of batteries and since I'm a chain vaper I go through a lot of batteries.
Did I mention back up?
Personally I was not able to fully quit until I decided I would never, ever, ever take another puff on a cig, and I just passed my first year mark without a puff. YMMV, that was how I had to do it. I am quite sure I am only one puff away from a total relapse. It's just the way I was. I don't ever plan on testing that idea.
Finally, sub-ohming is not all it's cracked up to be. It is really about the power. A 30-50W device will give you a great vape at any usable resistance value. If you get something like the Subox you may find, as I did, that I get a great vape on 0.5 ohm coils and 1.x ohm coils, at the same power level and I personally like the 25-35W range, depending on things.