I like the bike in #1 post. Is it the old fashioned Truck Bike, where the basket is attached to the frame (so it doesn't affect the steering so much)?
I like the Extracycle type cargo bikes also. (They look like mountain bikes, but the frame is longer, and the rear rack is part of the frame with welded tubes. A lot of people carry kids and groceries on them.)
I think for major weight, wouldn't you want a trike with a big box or basket in the back? That seems the best idea to me. I have seen loaded-touring or self-supporting touring cyclists (motored or not) carry 70-100lb of gear.
I have a wald steel rack and a milk crate and have carried about 60lb of groceries in and on it. I once carried a book bag loaded up with canned goods, and the bike pulled just fine with the 44tooth, but it was difficult to get on and off the bike.