There is no *best* setup. What works is what works for you. I have a frankensetup where I'm vaping a small, MTL nautilus tank (I do have a sub-ohm tank, rarely use it), on an IPV-5 regulated mod, which has two batteries, which I certainly don't *need*, I pay little attention to how often I change the batteries, but it's usually more than a day (probably). I carry spares (safely, in a battery box, in my purse) that way, I don't really have to constantly be checking battery levels... The setup LOOKS awful (my son recommended that mod and I like it a lot, but it's really unneccessary, IMO, with using 14 watts to vape (though it's nice to be able to sub-ohm, also) also, it looks really horrible for someone going for aesthetics) but I like it as it is sturdy, durable, and reliable. I'm going to be getting some other mods later, for backups (and a few more tanks) but right now I'm focusing on not quitting, so my setup works great (for me). I'd probably recommend watching some Youtube reviews and seeing what looks like might work for you....
Anna