We have the Thetford Smart tote - 18 Gallon Tank with Handle. I also have a 10 gallon tank that we can lift into the back of the truck.
http://www.campingworld.com/shopping/item/Thetford-SmartTote-LX-Portable-Waste-Tank-18-Gallon/37870/&?&cvsfa=2734&cvsfe=2&cvsfhu=3337383730
We use it when we go to some state parks for longer that 3 nights in the summer. Use it mainly for dumping our gray water tanks - wife prefers to use the shower in the RV. Also, need it for the gray tank that the kitchen sink drains to.
We have to pull it for about a mile to the dump station - pull slow to preserve the wheels.
I only dry camp a few times a year. I have 2 12V batteries in the trailer. I have a 4000 Yamaha generator - so I can run the AC a few times during the day to cool down the RV. If I did not run the AC I would purchase a 2000 watt Honda or Yamaha generator (much lighter).