So you want to hook up a power inverter via the 12volt plug in the Xterra to power your Alienbee's while out on location?

I honestly have no clue if that would be a good idea or if it would fry your setup to the high heavens. I have always been all things electrical dumb.

I have a set of studio Novatrons and have toyed with that idea as well, but have never had the guts to try it nor look it up and see if its even a good idea.

Whatever happened to ElectroKen? He would be the ideal person to answer your voltage question.

If you want a portable setup - I think the pocket wizards or SU-800 would be your best options. The SU-800 would be more economical since you wouldn't need to buy separate receivers for each flash and you'd be able to use TTL. You would just have range limitations since IR isn't as flexible as Radio.