Hi, welcome to the forum.
You had some good advise here. But I'll pitch in as well.
First of all here here some good
info about RBA's. And here is some
info about batteries, and here, you've got
more info about batteries.
Here is a
cheat sheet concerning safe resistances vs batteries.
You will find a
ohms law calculator here.
Now, if you want to be able to vape through the day using the least numbers of batteries as possible, go with the 18650 size batteries. However, when choosing a battery, don't go with the higher mAh rating. A high the amp limit or max. discharge rate is what you want to aim for.
If you don't want to chase clouds, there is absolutely no point in building dual coils. A single 0.8 to 1.1 ohm coil is easier to do and will be more than enough to satisfy your needs and you will be in the "safe resistance limit" for pretty much every good IMR batteries that are out there.
The kick 2 would be a great way to add safety to your device. Not only does the kick contains eletronic battery protection but it would allow you to build a 2.0ish coil and provide enough power for it to be satisfying.
Vape on.... Vape safe!!
EDIT: I would strongly suggest a Kayfun lite atomizer, it doesnt leak, tastes like a dripper and convinient as a tank... You can easily find clones of it out there.