It sounds to me like your instincts are spot on, based on what you're looking for.
The volt is a KR808, which is what I started with too.
It has great vapor production for its size. The vapor it produces is also quite hot, which gives good throat hit. The battery delivers 3.7 volts, which you'd otherwise only get with Riva/KGo style batteries and above. It also lasts longer than 510s of the same size. Going from smoking a pack a day, I only had to charge it about twice a day to keep up. That's with just one battery. With two of them and a PCC, you should be in good shape. As for carto life: My first week I used 11-12 cartos vs the to 6-7 packs of camel 99s I would have smoked otherwise. Overall, it's as close to a real cig feel as it gets.
Do note that even at that size, it can never be exactly the same as a real one. It's still heavier. It's hard. Holding it in your mouth, hands free, generally doesn't work too well. Most tobacco flavors aren't anywhere near the real thing. Definitely not the prefilled carto flavors. Nothing is burning, after all. At the very best, you should only expect it to taste the way tobacco smells when not lit. Although there are some liquids out there that try to imitate the burning tobacco taste.
Automatics are really convenient seeing as you just drag on them and they work. But a manual button gives you more control. You can get more vapor and better taste out of it, once you get the hang of it. Just takes some experimenting till you have a technique you're comfortable with down. Using the button quickly becomes second nature, too. You don't even think about it after a while.
Edit: But if you feel an automatic is what would be best for you, don't let anyone deter you. Manuals do force you to hold it differently. My first one was automatic and it got the job done. I'm still here, after all. And while I have many other options now, I still use it when I'm out and about. Just "blends in" better. For the most part, only smokers notice it's not real. Most people will glance your way, see you holding something white and yellow with a red glow on the end, and move along without second thought.
I haven't really had any leakage issues with mine at all. If you're paranoid, you can unscrew the carto when you're not using it and put the rubber plugs back on it. But, unless overfilled, KR808 cartos are very reliable in that department.