How about one of these simple passthrough-only power sources?
What would make this a lot better is to have the switch automatic, rather than push-button manual. That way, you can keep it in your mouth and just inhale while typing to activate the atomizer... no need to push the button to heat up the coil. Not sure if they make these in auto, though.
Keep in mind, you will still need to provide a clearo/carto with this. Might add to the weight, depending on what you choose.