So what 'backcountry' trailer need do you have? I.e. give us an example of a trip you did in which your experience would have been better had you had a trailer? Or an example of a trip you would have done if you had a trailer?
I'm a fan of off-road trailers in the right situations, but for those with pick-ups and trips under a week, I really don't know what advantages if any a trailer is going to offer particularly given your criteria to also use it as a utility trailer. I get the need/want to have it dual purpose, completely logical but that means its likely not going to have all of your camping gear organized and stowed thus your still loading and unloading it each trip. If you don't have enough room in the Tundra or Tacoma I understand the need, but if you don't have enough room in the Tundra or Tacoma your either packing waaaaay too much stuff or your hauling around 4 adults and gear/food for a months self supported travel. I'm not trying to bust your chops here, just trying to grasp what your actual 'back-country' trailer need is. Sounds to me like you've in search of a problem because you have the answer. Go on some backcountry trips first and decide if you need a trailer, furthermore that will tell you what type of trailer it needs to be to solve you actual needs.