Towbert,
I did call and speak with the folks at Zamp Solar, they are short on supply due to the long shoreman strike somewhere. Hope you found what you were after elsewhere. I did learn though from Zamp Solar that soon they will be sourcing their material and labor here in the USA. The gentleman I spoke with said that sometime after January 2016, their units would be made in Oregon!!!!
We try to buy made in USA as much as possible so this will be a win win for us. We plan on the 120 watt portable unit, some overkill I'm sure, but it may make up for some of those somewhat cloudy days when not getting the full 6.84 amps per hour.