I don't know what makes one better than the next other than wire gauge, etc, but tech-aero.net is where I'm getting mine. They are made by an electrical->computer engineer and used widely in the pattern community (which demands the best in reliability). Lots of options for redundant batteries and charging ports, etc. I've met the proprietor too, he's a good guy and I'm more than happy to give him business

http://www.tech-aero.net/