I wouldn't be inclined to pay $900+ on the Bushtrekka rig, nor $500-600 for the the EDAR. You can buy a used trailer for $35-$100 at yard sales, flea markets, or even ebay & craigslist. It would be a simple job to replace the cloth with an aluminum sheet bottom and/or sides. I'm doing this with my old Burley D'Lite, which is rated for 100lbs with the cloth wrapper supporting the weight. An aluminum bottom will increase the weight handling, although you're not likely to want or need that capacity. Other trailers have similar limits....just look them up. My Burley is over 20 years old and handles real nice. I've never had it tip over at any speed, loaded or not, but a much longer series of rides may change that. What a two-wheel trailer WILL do much cheaper is haul your tent-cot, lawn chair, and other gear cheaply and reliable with less stress on your trailer frame than what the BushTrekka will have with it's small tires. Same for the EDAR: small tires are a bumpy liability. Also, I see no need to sleep on top of the luggage either, as the tent-cot already is off the ground when set up. I intend to have a tent-hammock along also, and a backpack. After all, everything I have is very lightweight. While I usually rode a Bike-E, a Recycled Recumbent (google it) would be even more comfy and stable, and I can put lower gears on it. Mine will be made from a mountain bike, which will give me the option of using wide knobbies or smaller high-pressure tires as needed. I'm a huge fan of versatility and multiple-use items.
What my plan also does is allow me to buy modular....one piece at a time, and at the best prices. You can pay $250-$1000 for a new trailer, but they're not likely to haul any more than a used one. The one thing I urge you to really consider in trailers is the axles. If your wheels mount outside of the frame with one mount point like the latest Burley's and dime-store models do, it might not hold more than 60lbs. The older model's have wheels that mount like bike wheels, with two mount points, and they mount INSIDE the frame tubes. One-sided wheel mounts simply won't hold as much weight as a two-sided mount will, but they, and the frame, will flex more. The frame tubes protect the wheels also, which doesn't happen with wheels mounted outside the frame. Schwinn and some others had the older frames with two-sided mounts for the wheels, as well.
These weight and convenience issues may not matter to you if you're not carrying a lot of weight, but I bet price will. Consider the price, as well as what you intend to do with it. In addition, not everyone wants to rip the cloth off their trailer to put a metal bottom and sides on, but it's an idea I intend to use, along with possibly lengthening the trailer. I have a solar panel I intend to mount on the top rails of my trailer.
I'm making plans to build a light cargo trailer, which willl also haul my bike stuff, but whether I end up in a trailer, or on a bike with tent/hammock, etc, I intend to be comfortable, and that means I'll be following my multi-use ideas throughout. Just some more ideas to share with the gang....