When I bought the trailer to tow my 4 wheeler around in I looked for the smallest one I could fit the machine into, now when I get where I'm going I just take the 4 wheeler off the trailer and hook the trailer to the 4 wheeler.
This probably doesn't apply to you lucky land owners
Seriously though, I've put alot of weight in my trailer with no problems, except for the skinny road tires tearing up the trails.