I personally do not own any of these (I have an MVP 2 which is a wonderful vv/vw mod). But I have heard good things about the vamo and tesla on here and the electronic cigarette reddit. idk if that helps but you can find them pretty cheap in the US if you do not want to go through fasttech. As far as I have heard RTD Vapor is a great and trustworthy place to get a nice battery and charger. They should all perform rather similarly, but again I haven't used any I'm just trying to help out based on what I have read.
If box mods don't bother you, I would highly suggest the MVP V2. It is extremely rugged, always reliable, and has a battery that lasts an amazingly long time (2600mah). I have used mine for up to a week without having to recharge. The past few days I have been
vaping it from when I get up to when I go to bed, and the battery lasted from tuesday to saturday.
Hope this helps, I am sure some other people with more experience with these specific mods will chime in with some additional info.