I have the vision spinner eGo twist with a KangerTech mini protank 2 but its kinda bulky in my pocket and I want one that is smaller and or lighter. I don't want a disposable one, I want preferably 3.0 - 6.0v I'm not worried about little battery life because I'd have a backup. I also want a good one not a cheap one. Suggestions please???? Thanks!