If you're looking for long battery life, I just got a Silver Bullet, which is a large battery mod. I received it yesterday, charged the battery and started vaping last night. I am still on the same battery and I smoke/vape like a madman! (Old 2+ pack a day chain smoker)
For a cool vape, try to stick with the VG juice. Only a handful of vendors sell it but the vapor really is a lot smoother and there's more of it (large volume of vapor). The only issue with VG is that it is VERY thick and syrupy - doesn't taste like syrup but it doesn't run like water. You will need to take care with it as it will take longer to absorb into a cart when filling and its sticky.