Look no further, you have found what your looking for. I have only changed the battery 3 times in 9 days, gone through about 4-5 ml of juice, and it just keeps getting better and better tasting.
As for the 6v question, sure it can do it but I have not seen a need for it with this model. It hits very very well, in fact it hits like a mule. I can't imagine running it at 6v, I have to be careful not to take in too much vapor as it is now.
The JuiceBox is my final mod purchase, unless in the future a version with a electric pump or something is made then it's a whole new ballgame, lol! Give it a try, I don't think you will be disappointed, and if you happen to be the one person that is disappointed I am positive that you can make someone's day by offering it up for sale. There will be someone out there that would gladly take it off your hands and not have to wait for theirs to be built.