Personally, I've had the same ideas in my head for a while in regards to my next future project. Build a trailer specifically for the vehicle, balanced perfectly, keep it as low as possible. Dedicated trailer for use as storage of the vehicle too.
My next project is going to be some tiny something. I want to have the ability to tow it with a Jeep or Yukon and not have the whole thing weight more than a big pop-up camper.
If you can net another 1-2mpg+, each long trip to go wheeling, it could save you hundreds of dollars. And if you didn't need that 3/4ton anymore, then your DD'ing mpg could go way up because you don't need the big engine anymore.
I would still want suspension on the trailer and I wouldn't want a dually setup.
P.S. Shouldn't have gotten out of quads....< $$$$