I was thinking electric, but the more I think about it, I'm moving towards gas simply because I can remove the regulator, put a QC on it and run it off the trailer gas system, and be able to have some control over the heat which electric doesn't afford, and I'm not going to deal with the mess associated with charcoal.
I'm using a 30K BTU propane burner from a fish cooker to run my big smoker at home. I set the temp with the gas control, put a pile of hickory in the pan, set it on top of the burner and go to bed. The cooking temp never changes and I only have to go out occasionally and throw on another piece of wood. That's a lot better than trying to regulate heat by messing with vents and dampers. I wish I had thought of that years ago.