I have a Step2 wagon with 4 tag-along trailors, and would like to motorized the main wagon to assist in pulling up hills, and heavier loads. I use the system to pull children, but will also be using it for pulling beer coolers, with a keg in the primary wagon. I'm looking for something I can walk beside and throttle (would be awesome to have a breaking method as a bonus. Not required). I just wanted to see if you guys have anything already in place for a project like this. I'll attach a sample picture, just imagine 3 additional single trailors in tow as well. Maybe 4 soon.