I wonder why you mention the batteries you did, is this just the line that your local shop carries or is this what you have seen as "popular" on this site? I think its important to think about not just that you are looking for as far as a battery to last you a whole year, but also what you plan on doing a year from now? Most of these batteries will work fine for off the shelf coils but fail if you progress into RBA type devices, also with most of these having batteries that are not user replaceable that will limit the total life of the battery. Its important to balance the "now budget" with the "tomorrow budget" it may make sense to look at a 20 / 30 watt device even if you are only going to be using off the shelf coils, also, look to find something with a user replaceable battery if you want it to last a long time as the first thing to go on a battery device you are going to be using 16 hours a day / 7 days a week will most likely be the battery.