Like Michael said, it ain't worth it. Just use the mytee boxes and or use a spider box and just buy the diff connections. The spider boxes cost $600 bucks new, but they go on eBay for $100 or so used, I have 4 of them.
If no power, rent a generator from Sunbelt or your local rental place. They'll deliver it for an extra fee usually $40-50 bucks depending on distance. It'll come w/ a 50 footer to connect to to the generator than to your spider box. You can also rent the 50 footer cord @ Sunbelt.
Offcourse you can charge for everything from the spider boxes, gensets, gas, power cables, monitoring, driving to/from site, etc.