After doing more research, it looks like I would need to go with a coilover shock type as the coil spring is what dampens the bump on compression and the shock absorber is what keeps the spring from oscillating when rebounding. I might be able to use a stock ATV or motorcyle spring setup since the trailer weight would be similar to those type of vehicles.
The coilover spring will need to be installed to the inner part of the radius as it will need to be compressed vs being extended while in operation. This will assist in keeping the trailer tire (along with gravity) pinned to the road. I might have to design a preload lever to allow me to hook up the trailer or it will be near to impossible to rotate the hitch adapter so I can insert the trailer tongue into the receiver hitch. More brain power required...
I guess if I git an adjustable coilover setup, I could always spin the collar down every time I need to connect/disconnect the trailer. We'll see...
I could probably even go with an airbag type of setup as it would be totally adjustable to load weight, but that's starting to git kinda expensive...
